[bug] additional cmake args after CMAKE_TOOLCHAIN_FILE will clear it

[HRXWEB]

env

ROS2: humble
ubuntu 20.04

I test the bug used the following CMakeLists.txt file

cmake_minimum_required(VERSION 3.12)
project(OpenMPTest)


if(CMAKE_TOOLCHAIN_FILE)
  message(AUTHOR_WARNING TOOLCHAINFILE: ${CMAKE_TOOLCHAIN_FILE})
else()
  message(AUTHOR_WARNING TOOLCHAINFILE: ${CMAKE_TOOLCHAIN_FILE})
endif()

if(COUT_INFO)
  message(AUTHOR_WARNING COUT_INFO: ON)
else()
  message(AUTHOR_WARNING COUT_INFO: OFF)
endif()
find_package(OpenMP REQUIRED)
find_package(backward_ros REQUIRED)

colcon

when I typed the command:

colcon build --cmake-force-configure --cmake-args -DCMAKE_VERBOSE_MAKEFILE=ON --cmake-args -DCMAKE_TOOLCHAIN_FILE="/root/cross_compile/cmake-toolchains/generic_linux.cmake"

it will output:

Starting >>> OpenMPTest
[2.695s] WARNING:colcon.colcon_cmake.task.cmake.build:Could not run installation step for package 'OpenMPTest' because it has no 'install' target
--- stderr: OpenMPTest
CMake Warning (dev) at CMakeLists.txt:6 (message):
  TOOLCHAINFILE:/root/cross_compile/cmake-toolchains/generic_linux.cmake
This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Warning (dev) at CMakeLists.txt:14 (message):
  COUT_INFO:OFF
This warning is for project developers.  Use -Wno-dev to suppress it.

---
Finished <<< OpenMPTest [2.37s]

Summary: 1 package finished [2.50s]
  1 package had stderr output: OpenMPTest

When I typed the command:

colcon build --cmake-force-configure --cmake-args -DCMAKE_VERBOSE_MAKEFILE=ON --cmake-args -DCMAKE_TOOLCHAIN_FILE="/root/cross_compile/cmake-toolchains/generic_linux.cmake" --cmake-args -DCOUT_INFO=ON

it will output:

Starting >>> OpenMPTest
[2.673s] WARNING:colcon.colcon_cmake.task.cmake.build:Could not run installation step for package 'OpenMPTest' because it has no 'install' target
--- stderr: OpenMPTest                         
CMake Warning (dev) at CMakeLists.txt:8 (message):
  TOOLCHAINFILE:
This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Warning (dev) at CMakeLists.txt:12 (message):
  COUT_INFO:ON
This warning is for project developers.  Use -Wno-dev to suppress it.

---
Finished <<< OpenMPTest [2.34s]

Summary: 1 package finished [2.48s]
  1 package had stderr output: OpenMPTest

cmake

When I typed the command:

cmake -DCMAKE_TOOLCHAIN_FILE="/root/cross_compile/cmake-toolchains/generic_linux.cmake"

it will output:

CMake Warning:
  No source or binary directory provided.  Both will be assumed to be the
  same as the current working directory, but note that this warning will
  become a fatal error in future CMake releases.


-- The C compiler identification is GNU 9.4.0
-- The CXX compiler identification is GNU 9.4.0
-- Check for working C compiler: /usr/bin/aarch64-linux-gnu-gcc
-- Check for working C compiler: /usr/bin/aarch64-linux-gnu-gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/aarch64-linux-gnu-g++
-- Check for working CXX compiler: /usr/bin/aarch64-linux-gnu-g++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Warning (dev) at CMakeLists.txt:6 (message):
  TOOLCHAINFILE:/root/cross_compile/cmake-toolchains/generic_linux.cmake
This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Warning (dev) at CMakeLists.txt:14 (message):
  COUT_INFO:OFF
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Found OpenMP_C: -fopenmp (found version "4.5") 
-- Found OpenMP_CXX: -fopenmp (found version "4.5") 
-- Found OpenMP: TRUE (found version "4.5")  
-- Found backward_ros: 1.0.1 (/root/sysroot/opt/ros3rd/share/backward_ros/cmake)
-- Found Python3: /usr/bin/python3.8 (found version "3.8.10") found components: Interpreter 
-- Could NOT find libdw (missing: LIBDW_LIBRARY LIBDW_INCLUDE_DIR) 
-- Could NOT find libbfd (missing: LIBBFD_LIBRARY LIBBFD_INCLUDE_DIR) 
-- BACKWARD_HAS_UNWIND=1
-- BACKWARD_HAS_BACKTRACE=0
-- BACKWARD_HAS_BACKTRACE_SYMBOL=1
-- BACKWARD_HAS_DW=0
-- BACKWARD_HAS_BFD=0
-- Could NOT find Backward (missing: BACKWARD_LIBRARIES) 
-- Configuring done
-- Generating done
-- Build files have been written to: /home/huangruixin/ws/src/OpenMPTest

When I typed the command:

cmake -DCMAKE_TOOLCHAIN_FILE="/root/cross_compile/cmake-toolchains/generic_linux.cmake" -DCOUT_INFO=ON

it will output:

CMake Warning:
  No source or binary directory provided.  Both will be assumed to be the
  same as the current working directory, but note that this warning will
  become a fatal error in future CMake releases.


-- The C compiler identification is GNU 9.4.0
-- The CXX compiler identification is GNU 9.4.0
-- Check for working C compiler: /usr/bin/aarch64-linux-gnu-gcc
-- Check for working C compiler: /usr/bin/aarch64-linux-gnu-gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/aarch64-linux-gnu-g++
-- Check for working CXX compiler: /usr/bin/aarch64-linux-gnu-g++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Warning (dev) at CMakeLists.txt:6 (message):
  TOOLCHAINFILE:/root/cross_compile/cmake-toolchains/generic_linux.cmake
This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Warning (dev) at CMakeLists.txt:12 (message):
  COUT_INFO:ON
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Found OpenMP_C: -fopenmp (found version "4.5") 
-- Found OpenMP_CXX: -fopenmp (found version "4.5") 
-- Found OpenMP: TRUE (found version "4.5")  
-- Found backward_ros: 1.0.1 (/root/sysroot/opt/ros3rd/share/backward_ros/cmake)
-- Found Python3: /usr/bin/python3.8 (found version "3.8.10") found components: Interpreter 
-- Could NOT find libdw (missing: LIBDW_LIBRARY LIBDW_INCLUDE_DIR) 
-- Could NOT find libbfd (missing: LIBBFD_LIBRARY LIBBFD_INCLUDE_DIR) 
-- BACKWARD_HAS_UNWIND=1
-- BACKWARD_HAS_BACKTRACE=0
-- BACKWARD_HAS_BACKTRACE_SYMBOL=1
-- BACKWARD_HAS_DW=0
-- BACKWARD_HAS_BFD=0
-- Could NOT find Backward (missing: BACKWARD_LIBRARIES) 
-- Configuring done
-- Generating done
-- Build files have been written to: /home/huangruixin/ws/src/OpenMPTest

Compare

By comparing the following two keywords, it can be observed that the issue lies with colcon rather than cmake.

1. TOOLCHAINFILE:XXX
2. COUT_INFO:XXX

[cottsay]

The syntax of the invocation should be:

colcon build --cmake-force-configure --cmake-args -DCMAKE_VERBOSE_MAKEFILE=ON -DCMAKE_TOOLCHAIN_FILE="/root/cross_compile/cmake-toolchains/generic_linux.cmake" -DCOUT_INFO=ON

You should not specify --cmake-args multiple times like this.

[HRXWEB]

The syntax of the invocation should be:

colcon build --cmake-force-configure --cmake-args -DCMAKE_VERBOSE_MAKEFILE=ON -DCMAKE_TOOLCHAIN_FILE="/root/cross_compile/cmake-toolchains/generic_linux.cmake" -DCOUT_INFO=ON

You should not specify --cmake-args multiple times like this.

Wow, thanks a lot.

But there is a natural use case for colcon --cmake-args -DCMAKE_TOOLCHAIN_FILE=fixed.cmake --packages-select <package> [--cmake-args *[*]], where the final cmake-args is optional and placed at the end for convenience of modification. Is it worth supporting this usage?

A note: after specify some --cmake-args in cc.mixin, the --cmake-args after it will not disable the args in cc.mixin. like,
colcon build --mixin cc --packages-select <package_name> --cmake-args -DCOUT_INFO=ON
The CMAKE_TOOLCHAIN_FILE will keep the value in cc.mixin:

{
    "build": {
        "cc": {
            "cmake-args": [
                "-DCMAKE_VERBOSE_MAKEFILE=ON",
                "-DCMAKE_TOOLCHAIN_FILE='/root/sysroot/toolchain.cmake'"
            ]
        }
    }
}