Hi,
I am on my way to build my first high-level LibCyphal/CPP-based Cyphal applications. I already did libcanard on STM32, and of course PyCyphal. Finally I would like to have a my_hello_world top-layer cpp-application that just compiles Libcyphal as a dependency:
my_hello_world
├── build
├── CMakeLists.txt
├── Hello
├── HelloWorld.cpp
├── LICENSE
├── Libcyphal
└── README.md
where HelloWorld.cpp can just include cyphal.hpp. What could possibly go wrong 
? I have been on this for two days, so I’ve done more, but I will just describe the gist here.
Naively Cloning LibCyphal
git clone git@github.com:OpenCyphal-Garage/libcyphal.git
cd libcyphal
mkdir build
cd build
cmake ..
which results in
CMake Warning at cmake/CMakeCommon.cmake:18 (message):
[...]
Cloning into 'libcanard'...
fatal: invalid reference: v4
CMake Error at /home/erics/libcyphal/build/libcanard-subbuild/libcanard-populate-prefix/tmp/libcanard-populate-gitclone.cmake:61 (message):
Failed to checkout tag: 'v4'
[...]
-- Configuring incomplete, errors occurred!
Fine. So apparently cmake envokes downloading libcanard at version 4 that does not exist. The tags arev3.2.0, 3.2.0, 3.1.2 …, 3.0.0 and 2.0.0 etc. Alright, let’s try v3.2.0 by editing libcyhal/cmake/modules/Findlibcanard.cmake.
which works fine
cmake ..
CMake Warning at cmake/CMakeCommon.cmake:18 (message):
Neither LIBCYPHAL_VERSION nor CYPHAL_PROJECT_VERSION was not set. Setting
LIBCYPHAL_VERSION to default of 0.0.0.
Call Stack (most recent call first):
CMakeLists.txt:8 (include)
-- Populating cetl
-- Configuring done (0.0s)
-- Generating done (0.0s)
-- Build files have been written to: /home/erics/libcyphal/build/cetl-subbuild
[ 11%] Performing update step for 'cetl-populate'
-- Fetching latest from the remote origin
[ 22%] No patch step for 'cetl-populate'
[ 33%] No configure step for 'cetl-populate'
[ 44%] No build step for 'cetl-populate'
[ 55%] No install step for 'cetl-populate'
[ 66%] No test step for 'cetl-populate'
[ 77%] Completed 'cetl-populate'
[100%] Built target cetl-populate
-- Populating libcanard
-- Configuring done (0.0s)
-- Generating done (0.0s)
-- Build files have been written to: /home/erics/libcyphal/build/libcanard-subbuild
[ 11%] Performing download step (git clone) for 'libcanard-populate'
Cloning into 'libcanard'...
HEAD is now at 551af7f ESP-IDF Component Continuous Integration (#229)
[ 22%] Performing update step for 'libcanard-populate'
-- Already at requested tag: v3.2.0
[ 33%] No patch step for 'libcanard-populate'
[ 44%] No configure step for 'libcanard-populate'
[ 55%] No build step for 'libcanard-populate'
[ 66%] No install step for 'libcanard-populate'
[ 77%] No test step for 'libcanard-populate'
[ 88%] Completed 'libcanard-populate'
[100%] Built target libcanard-populate
-- Found libcanard: /home/erics/libcyphal/external/libcanard
-- Populating libudpard
-- Configuring done (0.0s)
-- Generating done (0.0s)
-- Build files have been written to: /home/erics/libcyphal/build/libudpard-subbuild
[ 11%] Creating directories for 'libudpard-populate'
[ 22%] Performing download step (git clone) for 'libudpard-populate'
Cloning into 'libudpard'...
Switched to a new branch 'v2'
Branch 'v2' set up to track remote branch 'v2' from 'origin'.
Submodule 'submodules/unity' (https://github.com/ThrowTheSwitch/Unity) registered for path 'submodules/unity'
Cloning into '/home/erics/libcyphal/external/libudpard/submodules/unity'...
Submodule path 'submodules/unity': checked out '0b899aec14d3a9abb2bf260ac355f0f28630a6a3'
[ 33%] Performing update step for 'libudpard-populate'
-- Fetching latest from the remote origin
[ 44%] No patch step for 'libudpard-populate'
[ 55%] No configure step for 'libudpard-populate'
[ 66%] No build step for 'libudpard-populate'
[ 77%] No install step for 'libudpard-populate'
[ 88%] No test step for 'libudpard-populate'
[100%] Completed 'libudpard-populate'
[100%] Built target libudpard-populate
-- Found libudpard: /home/erics/libcyphal/external/libudpard
-- Found clangformat: /usr/bin/clang-format
-- The CXX compiler identification is GNU 11.4.0
-- The C compiler identification is GNU 11.4.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Using clang-tidy: /usr/bin/clang-tidy
-- Populating public_regulated_data_types
-- Configuring done (0.0s)
-- Generating done (0.0s)
-- Build files have been written to: /home/erics/libcyphal/build/public_regulated_data_types-subbuild
[ 11%] Creating directories for 'public_regulated_data_types-populate'
[ 22%] Performing download step (git clone) for 'public_regulated_data_types-populate'
Cloning into 'public_regulated_data_types'...
HEAD is now at f9f6790 Hotfix: reduce the extent of ExecuteCommand.1.3 (#147)
[ 33%] Performing update step for 'public_regulated_data_types-populate'
-- Already at requested ref: f9f67906cc0ca5d7c1b429924852f6b28f313cbf
[ 44%] No patch step for 'public_regulated_data_types-populate'
[ 55%] No configure step for 'public_regulated_data_types-populate'
[ 66%] No build step for 'public_regulated_data_types-populate'
[ 77%] No install step for 'public_regulated_data_types-populate'
[ 88%] No test step for 'public_regulated_data_types-populate'
[100%] Completed 'public_regulated_data_types-populate'
[100%] Built target public_regulated_data_types-populate
-- Found public_regulated_data_types: /home/erics/libcyphal/external/public_regulated_data_types
-- Found Python3: /usr/bin/python3.10 (found version "3.10.12") found components: Interpreter
-- nnvg:/home/erics/.local/bin/nnvg --version: 2.3.1
-- Found nnvg: 2.3.1
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:163 (_init_nnvg_command_args)
CMakeLists.txt:45 (define_nunavut_support_target)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
CMakeLists.txt:50 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
CMakeLists.txt:50 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
-- Found googletest: /home/erics/libcyphal/external/googletest
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
test/unittest/CMakeLists.txt:20 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
test/unittest/CMakeLists.txt:20 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
docs/examples/CMakeLists.txt:27 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
docs/examples/CMakeLists.txt:27 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
-- IS_POSIX=TRUE
-- IS_LINUX=TRUE
-- EXAMPLES_PLATFORM_LIBS=examples_platform_posix;examples_platform_linux
-- Example: 0_transport/example_0_transport_1_heartbeat_getinfo_udp.cpp
-- Example: 0_transport/example_0_transport_2_heartbeat_getinfo_linux_can.cpp
-- Example: 1_presentation/example_1_presentation_0_hello_raw_pubsub_udp.cpp
-- Example: 1_presentation/example_1_presentation_1_ping_user_service_udp.cpp
-- Example: 1_presentation/example_1_presentation_2_heartbeat_getinfo_udp.cpp
-- Example: 1_presentation/example_1_presentation_3_hb_getinfo_ping_linux_can.cpp
-- Example: 2_application/example_2_application_0_node_hb_getinfo_udp.cpp
-- Found Doxygen: /usr/bin/doxygen (found version "1.9.1") found components: doxygen dot
-- TODO: add GNU/Linux demos
-- -------------------------------------------------------------------
| libcyphal
-- -------------------------------------------------------------------
LIBCYPHAL_ROOT: /home/erics/libcyphal/
LIBCYPHAL_INCLUDE: /home/erics/libcyphal/include
LIBCYPHAL_VERSION: 0.0.0
LIBCYPHAL_INTROSPECTION_TRACE_ENABLE: 0
LIBCYPHAL_INTROSPECTION_ENABLE_ASSERT: 0
CETLVAST_CPP_STANDARD: 14
CMAKE_PROJECT_NAME: libcyphal
CMAKE_SOURCE_DIR: /home/erics/libcyphal
CMAKE_CURRENT_SOURCE_DIR: /home/erics/libcyphal
CMAKE_BINARY_DIR: /home/erics/libcyphal/build
CMAKE_CURRENT_BINARY_DIR: /home/erics/libcyphal/build
CMAKE_MODULE_PATH: /home/erics/libcyphal/cmake/modules;/home/erics/libcyphal/external/cetl/cetlvast/cmake/modules
CMAKE_MESSAGE_LOG_LEVEL: STATUS
CMAKE_INSTALL_PREFIX: /home/erics/libcyphal/build
CMAKE_BUILD_TYPE:
FETCHCONTENT_FULLY_DISCONNECTED: OFF
CETL
CETL_ENABLE_DEBUG_ASSERT: 0
Standard Library
LIBCXX_ENABLE_ASSERTIONS: 0
-- ------------------------------------------------------------------
-- [ Build Kit ]-------------------------------------------
CMAKE_TOOLCHAIN_FILE: (not set)
CETLVAST_FLAG_SET: /home/erics/libcyphal/cmake/compiler_flag_sets/default.cmake
CMAKE_CXX_COMPILER_[ID-VER]: GNU-11.4.0
CMAKE_C_COMPILER_[ID-VER]: GNU-11.4.0
CMAKE_AR: /usr/bin/ar
CMAKE_LINKER: /usr/bin/ld
CMAKE_RANLIB: /usr/bin/ranlib
CMAKE_[lang]_PLATFORM_ID: Linux
-----------------------------------------------------------
-- Configuring done (9.7s)
-- Generating done (0.2s)
-- Build files have been written to: /home/erics/libcyphal/build
Ok. But we can see nothing was actually built. So
cd build
make
which fails with a ton of clang-formatted errors. So …
cd ~ # libcyphal is in home, whereever you cloned to code to
find libcyphal -name "*.hpp" -exec clang-format -i {} \;
and again
cd libcyphal/build
make
which fails again, but more spectacularly
make
[ 1%] Built target canard
[ 5%] Built target udpard
Formatting [1/62] libcyphal/application/node.hpp
Formatting [2/62] libcyphal/application/node/get_info_provider.hpp
Formatting [3/62] libcyphal/application/node/heartbeat_producer.hpp
Formatting [4/62] libcyphal/application/node/registry_provider.hpp
Formatting [5/62] libcyphal/application/registry/register.hpp
Formatting [6/62] libcyphal/application/registry/register_impl.hpp
Formatting [7/62] libcyphal/application/registry/registry.hpp
Formatting [8/62] libcyphal/application/registry/registry_impl.hpp
Formatting [9/62] libcyphal/common/cavl/cavl.hpp
Formatting [10/62] libcyphal/common/crc.hpp
Formatting [11/62] libcyphal/config.hpp
Formatting [12/62] libcyphal/errors.hpp
Formatting [13/62] libcyphal/executor.hpp
Formatting [14/62] libcyphal/platform/single_threaded_executor.hpp
Formatting [15/62] libcyphal/platform/storage.hpp
Formatting [16/62] libcyphal/presentation/client.hpp
Formatting [17/62] libcyphal/presentation/client_impl.hpp
Formatting [18/62] libcyphal/presentation/common_helpers.hpp
Formatting [19/62] libcyphal/presentation/presentation.hpp
Formatting [20/62] libcyphal/presentation/presentation_delegate.hpp
Formatting [21/62] libcyphal/presentation/publisher.hpp
Formatting [22/62] libcyphal/presentation/publisher_impl.hpp
Formatting [23/62] libcyphal/presentation/response_promise.hpp
Formatting [24/62] libcyphal/presentation/server.hpp
Formatting [25/62] libcyphal/presentation/server_impl.hpp
Formatting [26/62] libcyphal/presentation/shared_object.hpp
Formatting [27/62] libcyphal/presentation/subscriber.hpp
Formatting [28/62] libcyphal/presentation/subscriber_impl.hpp
Formatting [29/62] libcyphal/time_provider.hpp
Formatting [30/62] libcyphal/transport/can/can_transport.hpp
Formatting [31/62] libcyphal/transport/can/can_transport_impl.hpp
Formatting [32/62] libcyphal/transport/can/delegate.hpp
Formatting [33/62] libcyphal/transport/can/media.hpp
Formatting [34/62] libcyphal/transport/can/msg_rx_session.hpp
Formatting [35/62] libcyphal/transport/can/msg_tx_session.hpp
Formatting [36/62] libcyphal/transport/can/rx_session_tree_node.hpp
Formatting [37/62] libcyphal/transport/can/svc_rx_sessions.hpp
Formatting [38/62] libcyphal/transport/can/svc_tx_sessions.hpp
Formatting [39/62] libcyphal/transport/contiguous_payload.hpp
Formatting [40/62] libcyphal/transport/errors.hpp
Formatting [41/62] libcyphal/transport/lizard_helpers.hpp
Formatting [42/62] libcyphal/transport/media_payload.hpp
Formatting [43/62] libcyphal/transport/msg_sessions.hpp
Formatting [44/62] libcyphal/transport/scattered_buffer.hpp
Formatting [45/62] libcyphal/transport/session.hpp
Formatting [46/62] libcyphal/transport/session_tree.hpp
Formatting [47/62] libcyphal/transport/svc_rx_session_base.hpp
Formatting [48/62] libcyphal/transport/svc_sessions.hpp
Formatting [49/62] libcyphal/transport/transfer_id_map.hpp
Formatting [50/62] libcyphal/transport/transport.hpp
Formatting [51/62] libcyphal/transport/types.hpp
Formatting [52/62] libcyphal/transport/udp/delegate.hpp
Formatting [53/62] libcyphal/transport/udp/media.hpp
Formatting [54/62] libcyphal/transport/udp/msg_rx_session.hpp
Formatting [55/62] libcyphal/transport/udp/msg_tx_session.hpp
Formatting [56/62] libcyphal/transport/udp/rx_session_tree_node.hpp
Formatting [57/62] libcyphal/transport/udp/svc_rx_sessions.hpp
Formatting [58/62] libcyphal/transport/udp/svc_tx_sessions.hpp
Formatting [59/62] libcyphal/transport/udp/tx_rx_sockets.hpp
Formatting [60/62] libcyphal/transport/udp/udp_transport.hpp
Formatting [61/62] libcyphal/transport/udp/udp_transport_impl.hpp
Formatting [62/62] libcyphal/types.hpp
[ 5%] Built target libcyphal-clang-format-check
[ 7%] Built target gtest
[ 9%] Built target dsdl_support-gen
[ 9%] Built target dsdl_public_types-gen
[ 11%] Built target dsdl_my_custom_types-gen
[ 12%] Built target gmock
[ 14%] Building CXX object test/unittest/CMakeFiles/test_get_info_provider__googletest_objlib.dir/application/node/test_get_info_provider.cpp.o
error: too many errors emitted, stopping now [clang-diagnostic-error]
/home/erics/libcyphal/build/uavcan/_register/Value_1_0.hpp:213:9: error: member initializer 'empty' does not name a non-static data member or base class [clang-diagnostic-error]
empty{allocator},
^~~~~~~~~~~~~~~~
/home/erics/libcyphal/build/uavcan/_register/Value_1_0.hpp:214:9: error: member initializer 'string' does not name a non-static data member or base class [clang-diagnostic-error]
string{allocator},
^~~~~~~~~~~~~~~~~
/home/erics/libcyphal/build/uavcan/_register/Value_1_0.hpp:215:9: error: member initializer 'unstructured' does not name a non-static data member or base class [clang-diagnostic-error]
unstructured{allocator},
^~~~~~~~~~~~~~~~~~~~~~~
/home/erics/libcyphal/build/uavcan/_register/Value_1_0.hpp:216:9: error: member initializer 'bit' does not name a non-static data member or base class [clang-diagnostic-error]
bit{allocator},
^~~~~~~~~~~~~~
/home/erics/libcyphal/build/uavcan/_register/Value_1_0.hpp:217:9: error: member initializer 'integer64' does not name a non-static data member or base class [clang-diagnostic-error]
integer64{allocator},
^~~~~~~~~~~~~~~~~~~~
/home/erics/libcyphal/build/uavcan/_register/Value_1_0.hpp:218:9: error: member initializer 'integer32' does not name a non-static data member or base class [clang-diagnostic-error]
integer32{allocator},
^~~~~~~~~~~~~~~~~~~~
/home/erics/libcyphal/build/uavcan/_register/Value_1_0.hpp:219:9: error: member initializer 'integer16' does not name a non-static data member or base class [clang-diagnostic-error]
integer16{allocator},
^~~~~~~~~~~~~~~~~~~~
/home/erics/libcyphal/build/uavcan/_register/Value_1_0.hpp:220:9: error: member initializer 'integer8' does not name a non-static data member or base class [clang-diagnostic-error]
integer8{allocator},
^~~~~~~~~~~~~~~~~~~
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:56:48: error: no matching member function for call to 'makeServer' [clang-diagnostic-error]
auto maybe_get_info_srv = presentation.makeServer<Service>();
~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
/home/erics/libcyphal/include/libcyphal/presentation/presentation.hpp:360:10: note: candidate template ignored: requirement 'detail::IsServiceTrait<uavcan::node::GetInfo_1_0, false>::value' was not satisfied [with Service = uavcan::node::GetInfo_1_0]
auto makeServer(typename ServiceServer<Service>::OnRequestCallback::Function&& on_request_cb_fn = {})
^
/home/erics/libcyphal/include/libcyphal/presentation/presentation.hpp:313:10: note: candidate function template not viable: requires at least argument 'service_id', but no arguments were provided
auto makeServer(const transport::PortId service_id,
^
/home/erics/libcyphal/include/libcyphal/presentation/presentation.hpp:343:10: note: candidate function template not viable: requires at least argument 'service_id', but no arguments were provided
auto makeServer(const transport::PortId service_id,
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:62:56: error: use of undeclared identifier 'Server' [clang-diagnostic-error]
return GetInfoProvider{presentation, cetl::get<Server>(std::move(maybe_get_info_srv))};
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:62:56: error: use of undeclared identifier 'Server'; did you mean 'presentation::Server'? [clang-diagnostic-error]
return GetInfoProvider{presentation, cetl::get<Server>(std::move(maybe_get_info_srv))};
^~~~~~
presentation::Server
/home/erics/libcyphal/include/libcyphal/presentation/server.hpp:166:7: note: 'presentation::Server' declared here
class Server final : public detail::ServerBase
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:65:5: error: constructor does not initialize these fields: server_ [cppcoreguidelines-pro-type-member-init,hicpp-member-init,-warnings-as-errors]
GetInfoProvider(GetInfoProvider&& other) noexcept
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:189:31: error: use of undeclared identifier 'ArrayCapacity' [clang-diagnostic-error]
return setStringField<ArrayCapacity::name>(response_.name, name);
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:201:31: error: use of undeclared identifier 'ArrayCapacity' [clang-diagnostic-error]
return setStringField<ArrayCapacity::certificate_of_authenticity>(response_.certificate_of_authenticity,
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:206:47: error: no type named 'ArrayCapacity' in 'uavcan::node::GetInfo::Response_1_0::_traits_' [clang-diagnostic-error]
using ArrayCapacity = Response::_traits_::ArrayCapacity;
~~~~~~~~~~~~~~~~~~~~^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:209:5: error: constructor does not initialize these fields: server_, response_ [cppcoreguidelines-pro-type-member-init,hicpp-member-init,-warnings-as-errors]
GetInfoProvider(presentation::Presentation& presentation, Server&& server)
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:209:63: error: unknown type name 'Server' [clang-diagnostic-error]
GetInfoProvider(presentation::Presentation& presentation, Server&& server)
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:209:72: error: parameter 'server' is unused [misc-unused-parameters,-warnings-as-errors]
GetInfoProvider(presentation::Presentation& presentation, Server&& server)
^~~~~~
/*server*/
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:212:21: error: no member named 'allocator_type' in 'uavcan::node::GetInfo::Response_1_0'; did you mean 'nunavut::support::options::allocator_type'? [clang-diagnostic-error]
, response_{Response::allocator_type{&presentation.memory()}}
^~~~~~~~~~~~~~~~~~~~~~~~
nunavut::support::options::allocator_type
/home/erics/libcyphal/build/nunavut/support/serialization.hpp:197:25: note: 'nunavut::support::options::allocator_type' declared here
constexpr std::uint32_t allocator_type = 247585418;
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:212:45: error: expected '}' [clang-diagnostic-error]
, response_{Response::allocator_type{&presentation.memory()}}
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:212:20: note: to match this '{'
, response_{Response::allocator_type{&presentation.memory()}}
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:242:5: error: unknown type name 'Server' [clang-diagnostic-error]
Server server_;
^
/home/erics/libcyphal/include/libcyphal/application/registry/register.hpp:231:104: error: parameter 'alloc' is unused [misc-unused-parameters,-warnings-as-errors]
inline uavcan::_register::Name_1_0 makeRegisterName(const uavcan::_register::Name_1_0::allocator_type& alloc,
^~~~~
/*alloc*/
/home/erics/libcyphal/include/libcyphal/presentation/presentation.hpp:99:7: error: destructor of 'Presentation' is public and non-virtual [cppcoreguidelines-virtual-class-destructor,-warnings-as-errors]
class Presentation final : private detail::IPresentationDelegate
^
/home/erics/libcyphal/include/libcyphal/presentation/presentation.hpp:99:7: note: make it public and virtual
class Presentation final : private detail::IPresentationDelegate
^
/home/erics/libcyphal/include/libcyphal/presentation/response_promise.hpp:342:7: error: destructor of 'ResponsePromise<void>' is public and non-virtual [cppcoreguidelines-virtual-class-destructor,-warnings-as-errors]
class ResponsePromise<void> final : public ResponsePromiseBase<transport::ScatteredBuffer, RawResponsePromiseFailure>
^
/home/erics/libcyphal/include/libcyphal/presentation/response_promise.hpp:342:7: note: make it public and virtual
class ResponsePromise<void> final : public ResponsePromiseBase<transport::ScatteredBuffer, RawResponsePromiseFailure>
^
/home/erics/libcyphal/include/libcyphal/presentation/server.hpp:284:7: error: destructor of 'RawServiceServer' is public and non-virtual [cppcoreguidelines-virtual-class-destructor,-warnings-as-errors]
class RawServiceServer final : public detail::ServerBase
^
/home/erics/libcyphal/include/libcyphal/presentation/server.hpp:284:7: note: make it public and virtual
class RawServiceServer final : public detail::ServerBase
^
/usr/lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/type_traits:2579:44: error: no type named 'type' in 'std::enable_if<false>'; 'enable_if' cannot be used to disable this declaration [clang-diagnostic-error]
using enable_if_t = typename enable_if<_Cond, _Tp>::type;
^~~~~
/home/erics/libcyphal/include/libcyphal/presentation/server.hpp:276:45: note: in instantiation of template type alias 'enable_if_t' requested here
template <typename Service, typename = std::enable_if_t<detail::IsServiceTrait<Service>::value>>
^
/home/erics/libcyphal/include/libcyphal/application/node/get_info_provider.hpp:207:41: note: in instantiation of default argument for 'ServiceServer<uavcan::node::GetInfo_1_0>' required here
using Server = presentation::ServiceServer<Service>;
^~~~~~~~~~~~~~~~~~~~~~
92534 warnings and 20 errors generated.
Error while processing /home/erics/libcyphal/test/unittest/application/node/test_get_info_provider.cpp.
Suppressed 93023 warnings (92525 in non-user code, 498 NOLINT).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
7 warnings treated as errors
make[2]: *** [test/unittest/CMakeFiles/test_get_info_provider__googletest_objlib.dir/build.make:79: test/unittest/CMakeFiles/test_get_info_provider__googletest_objlib.dir/application/node/test_get_info_provider.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:894: test/unittest/CMakeFiles/test_get_info_provider__googletest_objlib.dir/all] Error 2
make: *** [Makefile:136: all] Error 2
So apparently there’s an issue generating the message header from the DSDL files. Fine. Maybe this is just not supposed to work.
- Trying out releases
Highest release number is v1.0.0rc-last, might as well give it a go.
cd libcyphal && git checkout v1.0.0rc-last
mkdir build
cd build && cmake -DCMAKE_POLICY_VERSION_MINIMUM=3.5 .. # suppressing minimum cmake error
CMake Deprecation Warning at CMakeLists.txt:5 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.
-- The C compiler identification is GNU 11.4.0
-- The CXX compiler identification is GNU 11.4.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Deprecation Warning at libuavcan/CMakeLists.txt:5 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.
-- Using C++11 (pass UAVCAN_USE_CPP03=1 to override)
-- Release build type: RelWithDebInfo
-- Adding UAVCAN Linux platform driver
CMake Deprecation Warning at libuavcan_drivers/posix/CMakeLists.txt:5 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.
CMake Deprecation Warning at libuavcan_drivers/linux/CMakeLists.txt:5 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
-- Using uavcan target; source dir: /home/erics/libcyphal/libuavcan
-- POSIX source dir: /home/erics/libcyphal/libuavcan_drivers/posix
-- Configuring done (0.4s)
-- Generating done (0.0s)
-- Build files have been written to: /home/erics/libcyphal/build
Success! Let’s build
make
[ 1%] Running dsdl compiler
/bin/sh: 1: PYTHON-NOTFOUND: not found
make[2]: *** [libuavcan/CMakeFiles/libuavcan_dsdlc.dir/build.make:89: libuavcan_dsdlc_run.stamp] Error 127
make[1]: *** [CMakeFiles/Makefile2:186: libuavcan/CMakeFiles/libuavcan_dsdlc.dir/all] Error 2
make: *** [Makefile:136: all] Error 2
huh? Turns out libuavcan/CMakeLists.txt has find_program(PYTHON python) which does not like that we don’t have a 3 at the end, so here we go: find_program(PYTHON python3)
make
CMake Deprecation Warning at CMakeLists.txt:5 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.
CMake Deprecation Warning at libuavcan/CMakeLists.txt:5 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.
-- Using C++11 (pass UAVCAN_USE_CPP03=1 to override)
-- Release build type: RelWithDebInfo
-- Adding UAVCAN Linux platform driver
CMake Deprecation Warning at libuavcan_drivers/posix/CMakeLists.txt:5 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.
CMake Deprecation Warning at libuavcan_drivers/linux/CMakeLists.txt:5 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.
-- Using uavcan target; source dir: /home/erics/libcyphal/libuavcan
-- POSIX source dir: /home/erics/libcyphal/libuavcan_drivers/posix
-- Configuring done (0.2s)
-- Generating done (0.0s)
-- Build files have been written to: /home/erics/libcyphal/build
[ 1%] Running dsdl compiler
Traceback (most recent call last):
File "/home/erics/libcyphal/libuavcan/dsdl_compiler/libuavcan_dsdlc", line 59, in <module>
from libuavcan_dsdl_compiler import run as dsdlc_run
File "/home/erics/libcyphal/libuavcan/dsdl_compiler/libuavcan_dsdl_compiler/__init__.py", line 17, in <module>
from uavcan import dsdl
ModuleNotFoundError: No module named 'uavcan'
make[2]: *** [libuavcan/CMakeFiles/libuavcan_dsdlc.dir/build.make:89: libuavcan_dsdlc_run.stamp] Error 1
make[1]: *** [CMakeFiles/Makefile2:186: libuavcan/CMakeFiles/libuavcan_dsdlc.dir/all] Error 2
make: *** [Makefile:136: all] Error 2
where uavcan is not found. The only Python module uavcan I am aware of is from a transpiled DSDL-file that I get from public_regulated_data_types. Ok, quickly jump into another project where I have that shit. And …
python3
Python 3.10.12 (main, Aug 15 2025, 14:32:43) [GCC 11.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import uavcan
>>> print(uavcan)
<module 'uavcan' from '${some_path}/python_compiled_messages/uavcan/__init__.py'>
>>> from uavcan import dsdl
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: cannot import name 'dsdl' from 'uavcan' (${some_path}/python_compiled_messages/uavcan/__init__.py)
>>>
so there is no dsdl in uavcan? What do you want from me ? Ok, giving up on this so far, and follow the CI (thanks @maksim.drachov 
)
Following the CI
Fresh start:
cd libcyphal && git reset --hard && git checkout main
which has libcyphal/.github-dir with a sonar.yml that does a bunch of stuff, including building with a build-tool. Yay . Reading it, and it seems all it does is:
python3 ./build-tools/bin/verify.py
which fails again:
python3 ./build-tools/bin/verify.py
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:163 (_init_nnvg_command_args)
CMakeLists.txt:45 (define_nunavut_support_target)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
CMakeLists.txt:50 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
CMakeLists.txt:50 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
test/unittest/CMakeLists.txt:20 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
test/unittest/CMakeLists.txt:20 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
docs/examples/CMakeLists.txt:27 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
docs/examples/CMakeLists.txt:27 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
-- Configuring done (4.5s)
-- Generating done (0.1s)
-- Build files have been written to: /home/erics/libcyphal/build
[0/2] Re-checking globbed directories...
[1/100] Building C object docs/examples/CMakeFiles/examples_platform_linux.dir/platform/linux/can/socketcan.c.o
FAILED: docs/examples/CMakeFiles/examples_platform_linux.dir/platform/linux/can/socketcan.c.o
/usr/bin/gcc -DCAVL_NO_ASSERT=1 -DLIBCYPHAL_VERSION=\"0.0.0\" -I/home/erics/libcyphal/external/libcanard/libcanard -g -pedantic -Wall -Wextra -Werror -Wfloat-equal -Wconversion -Wunused-parameter -Wunused-variable -Wunused-value -Wcast-align -Wmissing-declarations -Wmissing-field-initializers -Wdouble-promotion -Wswitch-enum -Wtype-limits -Wno-error=array-bounds -O0 -DDEBUG -ggdb -MD -MT docs/examples/CMakeFiles/examples_platform_linux.dir/platform/linux/can/socketcan.c.o -MF docs/examples/CMakeFiles/examples_platform_linux.dir/platform/linux/can/socketcan.c.o.d -o docs/examples/CMakeFiles/examples_platform_linux.dir/platform/linux/can/socketcan.c.o -c /home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c
In file included from /home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:11:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.h:56:58: error: ‘struct CanardFrame’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
56 | int16_t socketcanPush(const SocketCANFD fd, const struct CanardFrame* const frame, const CanardMicrosecond timeout_usec);
| ^~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.h:70:29: error: ‘struct CanardFrame’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
70 | struct CanardFrame* const out_frame,
| ^~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:136:58: error: ‘struct CanardFrame’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
136 | int16_t socketcanPush(const SocketCANFD fd, const struct CanardFrame* const frame, const CanardMicrosecond timeout_usec)
| ^~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:136:9: error: conflicting types for ‘socketcanPush’; have ‘int16_t(const SocketCANFD, const struct CanardFrame * const, const CanardMicrosecond)’ {aka ‘short int(const int, const struct CanardFrame * const, const long unsigned int)’}
136 | int16_t socketcanPush(const SocketCANFD fd, const struct CanardFrame* const frame, const CanardMicrosecond timeout_usec)
| ^~~~~~~~~~~~~
In file included from /home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:11:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.h:56:9: note: previous declaration of ‘socketcanPush’ with type ‘int16_t(const SocketCANFD, const struct CanardFrame * const, const CanardMicrosecond)’ {aka ‘short int(const int, const struct CanardFrame * const, const long unsigned int)’}
56 | int16_t socketcanPush(const SocketCANFD fd, const struct CanardFrame* const frame, const CanardMicrosecond timeout_usec);
| ^~~~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c: In function ‘socketcanPush’:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:138:34: error: invalid use of undefined type ‘const struct CanardFrame’
138 | if ((frame == NULL) || (frame->payload.data == NULL) || (frame->payload.size > UINT8_MAX))
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:138:67: error: invalid use of undefined type ‘const struct CanardFrame’
138 | if ((frame == NULL) || (frame->payload.data == NULL) || (frame->payload.size > UINT8_MAX))
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:150:27: error: invalid use of undefined type ‘const struct CanardFrame’
150 | cfd.can_id = frame->extended_can_id | CAN_EFF_FLAG;
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:151:37: error: invalid use of undefined type ‘const struct CanardFrame’
151 | cfd.len = (uint8_t) frame->payload.size;
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:154:38: error: invalid use of undefined type ‘const struct CanardFrame’
154 | (void) memcpy(cfd.data, frame->payload.data, frame->payload.size);
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:154:59: error: invalid use of undefined type ‘const struct CanardFrame’
154 | (void) memcpy(cfd.data, frame->payload.data, frame->payload.size);
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:159:34: error: invalid use of undefined type ‘const struct CanardFrame’
159 | const size_t mtu = (frame->payload.size > CAN_MAX_DLEN) ? CANFD_MTU : CAN_MTU;
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c: At top level:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:169:29: error: ‘struct CanardFrame’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
169 | struct CanardFrame* const out_frame,
| ^~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:168:9: error: conflicting types for ‘socketcanPop’; have ‘int16_t(const SocketCANFD, struct CanardFrame * const, CanardMicrosecond * const, const size_t, void * const, const CanardMicrosecond, _Bool * const)’ {aka ‘short int(const int, struct CanardFrame * const, long unsigned int * const, const long unsigned int, void * const, const long unsigned int, _Bool * const)’}
168 | int16_t socketcanPop(const SocketCANFD fd,
| ^~~~~~~~~~~~
In file included from /home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:11:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.h:69:9: note: previous declaration of ‘socketcanPop’ with type ‘int16_t(const SocketCANFD, struct CanardFrame * const, CanardMicrosecond * const, const size_t, void * const, const CanardMicrosecond, _Bool * const)’ {aka ‘short int(const int, struct CanardFrame * const, long unsigned int * const, const long unsigned int, void * const, const long unsigned int, _Bool * const)’}
69 | int16_t socketcanPop(const SocketCANFD fd,
| ^~~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c: In function ‘socketcanPop’:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:265:48: error: invalid application of ‘sizeof’ to incomplete type ‘struct CanardFrame’
265 | (void) memset(out_frame, 0, sizeof(struct CanardFrame));
| ^~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:268:18: error: invalid use of undefined type ‘struct CanardFrame’
268 | out_frame->extended_can_id = sockcan_frame.can_id & CAN_EFF_MASK;
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:269:18: error: invalid use of undefined type ‘struct CanardFrame’
269 | out_frame->payload.size = sockcan_frame.len;
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:270:18: error: invalid use of undefined type ‘struct CanardFrame’
270 | out_frame->payload.data = payload_buffer;
| ^~
cc1: all warnings being treated as errors
[11/100] Building CXX object _deps/googletest-build/googletest/CMakeFiles/gtest.dir/src/gtest-all.cc.o
ninja: build stopped: subcommand failed.
Ha, I’ve seen this before. It’s when the libcanard library is too “new” where the CanardFrame struct is not used this way anymore. Some breaking change a couple months back. I’ve actually not updated libcanard in my stm32 projects because of this. Ok, so we need to revert to an earlier libcanard-version. From my stm32 bs, I remember a specific commit-ID still worked, so let’s check it out.
cd external/libcanard
git branch -a
* (HEAD detached at v3.2.0)
master
remotes/origin/HEAD -> origin/master
remotes/origin/master
Yes, breaking change was from v2.x to v3.x. So.
cd external/libcanard
git checkout 03fc5fecc2c81bd6bfc6e474af8059fca2db4647
cd ~/libcyphal
python3 ./build-tools/bin/verify.py
which produces
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:163 (_init_nnvg_command_args)
CMakeLists.txt:45 (define_nunavut_support_target)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
CMakeLists.txt:50 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
CMakeLists.txt:50 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
test/unittest/CMakeLists.txt:20 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
test/unittest/CMakeLists.txt:20 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
docs/examples/CMakeLists.txt:27 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
docs/examples/CMakeLists.txt:27 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
-- Configuring done (4.0s)
-- Generating done (0.1s)
-- Build files have been written to: /home/erics/libcyphal/build
[0/2] Re-checking globbed directories...
[1/100] Building C object docs/examples/CMakeFiles/examples_platform_linux.dir/platform/linux/can/socketcan.c.o
FAILED: docs/examples/CMakeFiles/examples_platform_linux.dir/platform/linux/can/socketcan.c.o
/usr/bin/gcc -DCAVL_NO_ASSERT=1 -DLIBCYPHAL_VERSION=\"0.0.0\" -I/home/erics/libcyphal/external/libcanard/libcanard -g -pedantic -Wall -Wextra -Werror -Wfloat-equal -Wconversion -Wunused-parameter -Wunused-variable -Wunused-value -Wcast-align -Wmissing-declarations -Wmissing-field-initializers -Wdouble-promotion -Wswitch-enum -Wtype-limits -Wno-error=array-bounds -O0 -DDEBUG -ggdb -MD -MT docs/examples/CMakeFiles/examples_platform_linux.dir/platform/linux/can/socketcan.c.o -MF docs/examples/CMakeFiles/examples_platform_linux.dir/platform/linux/can/socketcan.c.o.d -o docs/examples/CMakeFiles/examples_platform_linux.dir/platform/linux/can/socketcan.c.o -c /home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c
In file included from /home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:11:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.h:56:58: error: ‘struct CanardFrame’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
56 | int16_t socketcanPush(const SocketCANFD fd, const struct CanardFrame* const frame, const CanardMicrosecond timeout_usec);
| ^~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.h:70:29: error: ‘struct CanardFrame’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
70 | struct CanardFrame* const out_frame,
| ^~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:136:58: error: ‘struct CanardFrame’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
136 | int16_t socketcanPush(const SocketCANFD fd, const struct CanardFrame* const frame, const CanardMicrosecond timeout_usec)
| ^~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:136:9: error: conflicting types for ‘socketcanPush’; have ‘int16_t(const SocketCANFD, const struct CanardFrame * const, const CanardMicrosecond)’ {aka ‘short int(const int, const struct CanardFrame * const, const long unsigned int)’}
136 | int16_t socketcanPush(const SocketCANFD fd, const struct CanardFrame* const frame, const CanardMicrosecond timeout_usec)
| ^~~~~~~~~~~~~
In file included from /home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:11:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.h:56:9: note: previous declaration of ‘socketcanPush’ with type ‘int16_t(const SocketCANFD, const struct CanardFrame * const, const CanardMicrosecond)’ {aka ‘short int(const int, const struct CanardFrame * const, const long unsigned int)’}
56 | int16_t socketcanPush(const SocketCANFD fd, const struct CanardFrame* const frame, const CanardMicrosecond timeout_usec);
| ^~~~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c: In function ‘socketcanPush’:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:138:34: error: invalid use of undefined type ‘const struct CanardFrame’
138 | if ((frame == NULL) || (frame->payload.data == NULL) || (frame->payload.size > UINT8_MAX))
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:138:67: error: invalid use of undefined type ‘const struct CanardFrame’
138 | if ((frame == NULL) || (frame->payload.data == NULL) || (frame->payload.size > UINT8_MAX))
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:150:27: error: invalid use of undefined type ‘const struct CanardFrame’
150 | cfd.can_id = frame->extended_can_id | CAN_EFF_FLAG;
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:151:37: error: invalid use of undefined type ‘const struct CanardFrame’
151 | cfd.len = (uint8_t) frame->payload.size;
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:154:38: error: invalid use of undefined type ‘const struct CanardFrame’
154 | (void) memcpy(cfd.data, frame->payload.data, frame->payload.size);
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:154:59: error: invalid use of undefined type ‘const struct CanardFrame’
154 | (void) memcpy(cfd.data, frame->payload.data, frame->payload.size);
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:159:34: error: invalid use of undefined type ‘const struct CanardFrame’
159 | const size_t mtu = (frame->payload.size > CAN_MAX_DLEN) ? CANFD_MTU : CAN_MTU;
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c: At top level:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:169:29: error: ‘struct CanardFrame’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
169 | struct CanardFrame* const out_frame,
| ^~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:168:9: error: conflicting types for ‘socketcanPop’; have ‘int16_t(const SocketCANFD, struct CanardFrame * const, CanardMicrosecond * const, const size_t, void * const, const CanardMicrosecond, _Bool * const)’ {aka ‘short int(const int, struct CanardFrame * const, long unsigned int * const, const long unsigned int, void * const, const long unsigned int, _Bool * const)’}
168 | int16_t socketcanPop(const SocketCANFD fd,
| ^~~~~~~~~~~~
In file included from /home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:11:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.h:69:9: note: previous declaration of ‘socketcanPop’ with type ‘int16_t(const SocketCANFD, struct CanardFrame * const, CanardMicrosecond * const, const size_t, void * const, const CanardMicrosecond, _Bool * const)’ {aka ‘short int(const int, struct CanardFrame * const, long unsigned int * const, const long unsigned int, void * const, const long unsigned int, _Bool * const)’}
69 | int16_t socketcanPop(const SocketCANFD fd,
| ^~~~~~~~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c: In function ‘socketcanPop’:
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:265:48: error: invalid application of ‘sizeof’ to incomplete type ‘struct CanardFrame’
265 | (void) memset(out_frame, 0, sizeof(struct CanardFrame));
| ^~~~~~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:268:18: error: invalid use of undefined type ‘struct CanardFrame’
268 | out_frame->extended_can_id = sockcan_frame.can_id & CAN_EFF_MASK;
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:269:18: error: invalid use of undefined type ‘struct CanardFrame’
269 | out_frame->payload.size = sockcan_frame.len;
| ^~
/home/erics/libcyphal/docs/examples/platform/linux/can/socketcan.c:270:18: error: invalid use of undefined type ‘struct CanardFrame’
270 | out_frame->payload.data = payload_buffer;
| ^~
cc1: all warnings being treated as errors
[2/100] Building C object docs/examples/CMakeFiles/examples_platform_posix.dir/platform/posix/udp/udp.c.o
[3/100] Building C object CMakeFiles/canard.dir/external/libcanard/libcanard/canard.c.o
[4/100] Building C object CMakeFiles/udpard.dir/external/libudpard/libudpard/udpard.c.o
[5/100] Running nnvg to generate headers for dsdl_support
[6/100] Running nnvg to generate headers for dsdl_my_custom_types
[7/100] Running nnvg to generate headers for dsdl_example_types
[8/100] Building CXX object _deps/googletest-build/googlemock/CMakeFiles/gmock_main.dir/src/gmock_main.cc.o
[9/100] Building CXX object _deps/googletest-build/googlemock/CMakeFiles/gmock.dir/src/gmock-all.cc.o
[10/100] Running nnvg to generate headers for dsdl_public_types
[11/100] Building CXX object _deps/googletest-build/googletest/CMakeFiles/gtest.dir/src/gtest-all.cc.o
ninja: build stopped: subcommand failed.
which has some issues with libcanard again, I believe. So maybe the commit was wrong. Try some other libcanard version then. Last push to main-branch of libcyphal was 8 months ago today (November 5th 2025), so let’s see which libcanard version was en vogue back then … Fuck it was libcanard v3.2.0 as of September 2024. So let’s checkout out master which is mostly updated 6 and 3 months ago.
cd libcyphal/external/libcanard
git checkout master
cd ..
python3 ./build-tools/bin/verify.py
which gives me
python3 ./build-tools/bin/verify.py
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:163 (_init_nnvg_command_args)
CMakeLists.txt:45 (define_nunavut_support_target)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
CMakeLists.txt:50 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
CMakeLists.txt:50 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
test/unittest/CMakeLists.txt:20 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
test/unittest/CMakeLists.txt:20 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:40 (cmake_parse_arguments):
The OUTPUT_FOLDER keyword was followed by an empty string or no value at
all. Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_OUTPUT_FOLDER variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:228 (_init_nnvg_command_args)
docs/examples/CMakeLists.txt:27 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
CMake Warning (dev) at cmake/modules/Findnnvg.cmake:87 (cmake_parse_arguments):
The ADD_TO_ALL keyword was followed by an empty string or no value at all.
Policy CMP0174 is not set, so cmake_parse_arguments() will unset the
ARG_ADD_TO_ALL variable rather than setting it to an empty string.
Call Stack (most recent call first):
cmake/modules/Findnnvg.cmake:298 (_define_nnvg_rules)
docs/examples/CMakeLists.txt:27 (add_dsdl_cpp_codegen)
This warning is for project developers. Use -Wno-dev to suppress it.
-- Configuring done (4.2s)
-- Generating done (0.1s)
-- Build files have been written to: /home/erics/libcyphal/build
[0/2] Re-checking globbed directories...
[1/100] Building C object CMakeFiles/canard.dir/external/libcanard/libcanard/canard.c.o
FAILED: CMakeFiles/canard.dir/external/libcanard/libcanard/canard.c.o
/usr/bin/gcc -DCAVL_NO_ASSERT=1 -DLIBCYPHAL_VERSION=\"0.0.0\" -I/home/erics/libcyphal/external/libcanard/libcanard -g -fPIC -pedantic -Wall -Wextra -Werror -Wfloat-equal -Wconversion -Wunused-parameter -Wunused-variable -Wunused-value -Wcast-align -Wmissing-declarations -Wmissing-field-initializers -Wdouble-promotion -Wswitch-enum -Wtype-limits -Wno-error=array-bounds -O0 -DDEBUG -ggdb -MD -MT CMakeFiles/canard.dir/external/libcanard/libcanard/canard.c.o -MF CMakeFiles/canard.dir/external/libcanard/libcanard/canard.c.o.d -o CMakeFiles/canard.dir/external/libcanard/libcanard/canard.c.o -c /home/erics/libcyphal/external/libcanard/libcanard/canard.c
/home/erics/libcyphal/external/libcanard/libcanard/canard.c:45:10: fatal error: cavl2.h: No such file or directory
45 | #include <cavl2.h>
| ^~~~~~~~~
compilation terminated.
[11/100] Building CXX object _deps/googletest-build/googletest/CMakeFiles/gtest.dir/src/gtest-all.cc.o
ninja: build stopped: subcommand failed.
Alright, apparently I am missing a lib?! Google-Search gives me nothing, but github-search tells me it’s some Cyphal-Specific thing, as it only appears in Cyphal code or issues. See Github Code search for #include <cavl2.h>
I tried to subsume what I did for the last two days and replicated all results exactly as described here. I also omitted my more stupid approaches.
If someone can help, please do.