ament_cmake_vendor_package

[XQSwx]

When cross-compiling the Humble version using colcon build, the following error occurs:

ament_cmake_vendor_package
CMake Error at CMakeLists.txt:4 (find_package):
By not providing "Findexlib.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "exlib", but
CMake did not find one.

Could not find a package configuration file provided by "exlib" with any of the following names:

exlibConfig.cmake
exlib-config.cmake

Add the installation prefix of "exlib" to CMAKE_PREFIX_PATH or set
"exlib_DIR" to a directory containing one of the above files. If "exlib"
provides a separate development package or SDK, be sure it has been installed.

Compilation Command

colcon build --cmake-args -DCMAKE_TOOLCHAIN_FILE=/home/andy/rk-linux5.10/buildroot/output/rockchip_rk3399/host/share/buildroot/toolchainfile.cmake -DCMAKE_FIND_ROOT_PATH=/home/andy/ros2_humble/install

toolchainfile.cmake

#
# Automatically generated file; DO NOT EDIT.
# CMake toolchain file for Buildroot
#

# In order to allow the toolchain to be relocated, we calculate the
# HOST_DIR based on this file's location: $(HOST_DIR)/share/buildroot
# and store it in RELOCATED_HOST_DIR.
# All the other variables that need to refer to HOST_DIR will use the
# RELOCATED_HOST_DIR variable.
string(REPLACE "/share/buildroot" "" RELOCATED_HOST_DIR ${CMAKE_CURRENT_LIST_DIR})

# Point cmake to the location where we have our custom modules,
# so that it can find our custom platform description.
list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR})

if(NOT DEFINED CMAKE_SYSTEM_NAME)
  set(CMAKE_SYSTEM_NAME Buildroot)
endif()
if(NOT DEFINED CMAKE_SYSTEM_VERSION)
  set(CMAKE_SYSTEM_VERSION 1)
endif()
if(NOT DEFINED CMAKE_SYSTEM_PROCESSOR)
  set(CMAKE_SYSTEM_PROCESSOR aarch64)
endif()

# Set the {C,CXX}FLAGS appended by CMake depending on the build type
# defined by Buildroot. CMake defaults these variables with -g and/or
# -O options, and they are appended at the end of the argument list,
# so the Buildroot options are overridden. Therefore these variables
# have to be cleared, so that the options passed in CMAKE_C_FLAGS do
# apply.
#
# Note:
#   if the project forces some of these flag variables, Buildroot is
#   screwed up and there is nothing Buildroot can do about that :(
if(NOT DEFINED CMAKE_C_FLAGS_DEBUG)
  set(CMAKE_C_FLAGS_DEBUG "" CACHE STRING "Debug CFLAGS")
endif()
if(NOT DEFINED CMAKE_C_FLAGS_RELEASE)
  set(CMAKE_C_FLAGS_RELEASE " -DNDEBUG" CACHE STRING "Release CFLAGS")
endif()

# Build type from the Buildroot configuration
if(NOT DEFINED CMAKE_BUILD_TYPE)
  set(CMAKE_BUILD_TYPE Release CACHE STRING "Buildroot build configuration")
endif()

# Buildroot defaults flags.
# If you are using this toolchainfile.cmake file outside of Buildroot and
# want to customize the compiler/linker flags, then:
# * set them all on the cmake command line, e.g.:
#     cmake -DCMAKE_C_FLAGS="-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g0 -D_FORTIFY_SOURCE=1 -DUSE_UPDATEENGINE=ON -DSUCCESSFUL_BOOT=ON -Dsome_custom_flag" ...
# * and make sure the project's CMake code extends them like this if needed:
#     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Dsome_definitions")
if(NOT DEFINED CMAKE_C_FLAGS)
  set(CMAKE_C_FLAGS "-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g0 -D_FORTIFY_SOURCE=1 -DUSE_UPDATEENGINE=ON -DSUCCESSFUL_BOOT=ON" CACHE STRING "Buildroot CFLAGS")
endif()
if(NOT DEFINED CMAKE_EXE_LINKER_FLAGS)
  set(CMAKE_EXE_LINKER_FLAGS "" CACHE STRING "Buildroot LDFLAGS for executables")
endif()
if(NOT DEFINED CMAKE_SHARED_LINKER_FLAGS)
  set(CMAKE_SHARED_LINKER_FLAGS "" CACHE STRING "Buildroot LDFLAGS for shared libraries")
endif()
if(NOT DEFINED CMAKE_MODULE_LINKER_FLAGS)
  set(CMAKE_MODULE_LINKER_FLAGS "" CACHE STRING "Buildroot LDFLAGS for module libraries")
endif()

if(NOT DEFINED CMAKE_INSTALL_SO_NO_EXE)
  set(CMAKE_INSTALL_SO_NO_EXE 0)
endif()

if(NOT DEFINED CMAKE_PROGRAM_PATH)
  set(CMAKE_PROGRAM_PATH "${RELOCATED_HOST_DIR}/bin")
endif()
if(NOT DEFINED CMAKE_SYSROOT)
  set(CMAKE_SYSROOT "${RELOCATED_HOST_DIR}/aarch64-buildroot-linux-gnu/sysroot")
endif()
if(NOT DEFINED CMAKE_FIND_ROOT_PATH)
  set(CMAKE_FIND_ROOT_PATH "${RELOCATED_HOST_DIR}/aarch64-buildroot-linux-gnu/sysroot")
endif()
if(NOT DEFINED CMAKE_FIND_ROOT_PATH_MODE_PROGRAM)
  set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
endif()
if(NOT DEFINED CMAKE_FIND_ROOT_PATH_MODE_PACKAGE)
  set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
endif()
if(NOT DEFINED CMAKE_FIND_ROOT_PATH_MODE_LIBRARY)
  set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
endif()
if(NOT DEFINED CMAKE_FIND_ROOT_PATH_MODE_INCLUDE)
  set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
endif()
set(ENV{PKG_CONFIG_SYSROOT_DIR} "${RELOCATED_HOST_DIR}/aarch64-buildroot-linux-gnu/sysroot")

# This toolchain file can be used both inside and outside Buildroot.
if(NOT DEFINED CMAKE_C_COMPILER)
  set(CMAKE_C_COMPILER "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-gcc")
endif()
if(1)
  if(NOT DEFINED CMAKE_CXX_FLAGS_DEBUG)
    set(CMAKE_CXX_FLAGS_DEBUG "" CACHE STRING "Debug CXXFLAGS")
  endif()
  if(NOT DEFINED CMAKE_CXX_FLAGS_RELEASE)
    set(CMAKE_CXX_FLAGS_RELEASE " -DNDEBUG" CACHE STRING "Release CXXFLAGS")
  endif()
  if(NOT DEFINED CMAKE_CXX_FLAGS)
    set(CMAKE_CXX_FLAGS "-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g0 -D_FORTIFY_SOURCE=1" CACHE STRING "Buildroot CXXFLAGS")
  endif()
  if(NOT DEFINED CMAKE_CXX_COMPILER)
    set(CMAKE_CXX_COMPILER "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-g++")
  endif()
endif()
if(0)
  if(NOT DEFINED CMAKE_Fortran_FLAGS_DEBUG)
    set(CMAKE_Fortran_FLAGS_DEBUG "" CACHE STRING "Debug Fortran FLAGS")
  endif()
  if(NOT DEFINED CMAKE_Fortran_FLAGS_RELEASE)
    set(CMAKE_Fortran_FLAGS_RELEASE " -DNDEBUG" CACHE STRING "Release Fortran FLAGS")
  endif()
  if(NOT DEFINED CMAKE_Fortran_FLAGS)
    set(CMAKE_Fortran_FLAGS "-Os -g0" CACHE STRING "Buildroot FCFLAGS")
  endif()
  if(NOT DEFINED CMAKE_Fortran_COMPILER)
    set(CMAKE_Fortran_COMPILER "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-gfortran")
  endif()
endif()

# For Qt6
if(NOT DEFINED QT_HOST_PATH)
  set(QT_HOST_PATH "${RELOCATED_HOST_DIR}")
endif()

if(NOT DEFINED QT_HOST_PATH_CMAKE_DIR)
  set(QT_HOST_PATH_CMAKE_DIR "${RELOCATED_HOST_DIR}/lib/cmake")
endif()

set(CMAKE_AR "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-ar")
set(CMAKE_AS "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-as")
set(CMAKE_LINKER "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-ld")
set(CMAKE_NM "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-nm")
set(CMAKE_RANLIB "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-ranlib")
set(CMAKE_READELF "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-readelf")
set(CMAKE_STRIP "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-strip")
set(CMAKE_OBJCOPY "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-objcopy")
set(CMAKE_OBJDUMP "${RELOCATED_HOST_DIR}/bin/aarch64-buildroot-linux-gnu-objdump")

[christophebedard]

What version/branch of this repo are you trying to build? Looks like exlib is a test package that was added after Humble: #429

[christophebedard]

Oh, no, it was backported to Humble too: #467

It would help to know:

1. What is in /home/andy/ros2_humble/install and how it was built
2. What you're building/what's in the workspace you're building with the colcon build ... command you provided

[MichaelOrlov]

@mjcarroll Friendly ping to comment about dependecies.

[XQSwx]

I compiled it in the Humble version, and the install directory does not have exlibConfig. cmake, but the build directory does. But I just can't find the dependency relationship

[XQSwx]

cmake_minimum_required(VERSION 3.15)
project(ament_cmake_vendor_package NONE)

find_package(ament_cmake_core REQUIRED)
find_package(ament_cmake_export_dependencies REQUIRED)

ament_export_dependencies(
ament_cmake_core
)

ament_package(
CONFIG_EXTRAS "ament_cmake_vendor_package-extras.cmake"
)

include(CTest)
if(BUILD_TESTING)
add_subdirectory(test)
endif()

install(
DIRECTORY cmake
DESTINATION share/${PROJECT_NAME}
)

I can pass by closing add_Subdirectory (test)

[XQSwx]

I suspect it's an installation issue because the build directory already has this file, but the install directory doesn't

[christophebedard]

Can you provide the exact command you used to build /home/andy/ros2_humble/install? Like colcon ...

[christophebedard]

I suspect it's an installation issue because the build directory already has this file, but the install directory doesn't

I think tests aren't usually installed to the install/ directory.

[XQSwx]

Build Command
colcon build --cmake-args -DCMAKE_PREFIX_PATH=$PWD/install -DCMAKE_FIND_ROOT_PATH=$PWD/install -DCMAKE_TOOLCHAIN_FILE=/buildroot/host/share/buildroot/toolchainfile.cmake

[christophebedard]

We could consider installing these tests to the install/ directory, but realistically you might hit the same issue with other packages, and you probably don't really need these specific tests.

Maybe other people have different opinions/suggestions.

[clalancette]

We could consider installing these tests to the install/ directory, but realistically you might hit the same issue with other packages, and you probably don't really need these specific tests.

In general, we don't install tests into the install directory, because they don't need to be installed; they only need to be available in the build directory to be run. That said, I don't know how all of this works together with cross-compilation.