Build option PICO_TOOLCHAIN_PATH has no effect

[josesimoes]

Was trying to use PICO_TOOLCHAIN_PATH to point to the location where I have it installed on my setup.
(I do NOT have gcc it on my path)

Turns out that this option has no effect because it's always cleared here.

As soon as I comment out this line, I can set the PICO_TOOLCHAIN_PATH option and pico_find_compiler happilly finds the compiler.

I can submit a PR with this fix if you want.

[kilograham]

how are you setting PICO_TOOLCHAIN_PATH? was this a fresh build directory?

[josesimoes]

how are you setting PICO_TOOLCHAIN_PATH? was this a fresh build directory?

Yes, it's a fresh build directory and I'm using VS Code ".vscode\cmake-variants.json" to set the build options.

[kilograham]

what i meant was how is it getting set from a cmake perspective? command line define, environment?

I know it works with -DPICO_TOOLCHAIN_PATH= on the command line, since i use that all the time!

[josesimoes]

I was using cmake-variants.json to build with CMake with the CMake Tools extension.

[josesimoes]

@kilograham do you use just -DPICO_TOOLCHAIN_PATH= or you actually have something in the path ahead of the = ?

[lurch]

I suspect Graham meant -DPICO_TOOLCHAIN_PATH=/path/to/toolchain

[kilograham]

yes, that is what I meant... also what OS are you on?

[josesimoes]

Windows 10, 64bits
VS Code 1.54.1
CMake tools 1.6.0

[josesimoes]

Follows the CMake logs, for completeness. On both the PICO_TOOLCHAIN_PATH is set trough .vscode\cmake-variants.json. Build folder cleaned.

With the original code:

[main] Configuring folder: pico-sdk 
[proc] Executing command: "C:/Program Files/CMake/bin/cmake.exe" --no-warn-unused-cli -DCMAKE_MAKE_PROGRAM:STRING=E:/nftools/Ninja/ninja.exe -DPICO_TOOLCHAIN_PATH:STRING=E:/nftools/GNU_Tools_ARM_Embedded/9-2020-q2-update/ -DPICO_COMPILER:STRING=pico_arm_gcc -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE -DCMAKE_BUILD_TYPE:STRING=Debug -He:/Github/pico-sdk -Be:/Github/pico-sdk/build -G Ninja
[cmake] Not searching for unused variables given on the command line.
[cmake] PICO_SDK_PATH is E:/Github/pico-sdk
[cmake] Defaulting PICO_PLATFORM to rp2040 since not specified.
[cmake] PICO compiler is pico_arm_gcc
[cmake] PICO_GCC_TRIPLE defaulted to arm-none-eabi
[cmake] CMake Error at cmake/preload/toolchains/find_compiler.cmake:28 (message):
[cmake]   Compiler 'arm-none-eabi-gcc' not found, you can specify search path with
[cmake]   "PICO_TOOLCHAIN_PATH".
[cmake] Call Stack (most recent call first):
[cmake]   cmake/preload/toolchains/pico_arm_gcc.cmake:20 (pico_find_compiler)
[cmake]   C:/Program Files/CMake/share/cmake-3.15/Modules/CMakeDetermineSystem.cmake:93 (include)
[cmake]   CMakeLists.txt:6 (project)
[cmake] 
[cmake] 
[cmake] CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage
[cmake] CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage
[cmake] CMake Error: CMAKE_ASM_COMPILER not set, after EnableLanguage
[cmake] -- Configuring incomplete, errors occurred!

With line 3 @ pico_pre_load_toolchain.cmake commented:

[cmake] -- Build files have been written to: E:/Github/pico-sdk/build
[main] Configuring folder: pico-sdk 
[proc] Executing command: "C:/Program Files/CMake/bin/cmake.exe" --no-warn-unused-cli -DCMAKE_MAKE_PROGRAM:STRING=E:/nftools/Ninja/ninja.exe -DPICO_TOOLCHAIN_PATH:STRING=E:/nftools/GNU_Tools_ARM_Embedded/9-2020-q2-update/ -DPICO_COMPILER:STRING=pico_arm_gcc -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE -DCMAKE_BUILD_TYPE:STRING=Debug -He:/Github/pico-sdk -Be:/Github/pico-sdk/build -G Ninja
[cmake] Not searching for unused variables given on the command line.
[cmake] PICO_SDK_PATH is E:/Github/pico-sdk
[cmake] Defaulting PICO_PLATFORM to rp2040 since not specified.
[cmake] PICO compiler is pico_arm_gcc
[cmake] PICO_GCC_TRIPLE defaulted to arm-none-eabi
[cmake] -- The C compiler identification is GNU 9.3.1
[cmake] -- The CXX compiler identification is GNU 9.3.1
[cmake] -- The ASM compiler identification is GNU
[cmake] -- Found assembler: E:/nftools/GNU_Tools_ARM_Embedded/9-2020-q2-update/bin/arm-none-eabi-gcc.exe
[cmake] Using regular optimized debug build (set PICO_DEOPTIMIZED_DEBUG=1 to de-optimize)
[cmake] Defaulting PICO target board to pico since not specified.
[cmake] Using board configuration from E:/Github/pico-sdk/src/boards/include/boards/pico.h
[cmake] -- Found Python3: C:/Program Files/Python39/python.exe (found version "3.9.2") found components:  Interpreter 
[cmake] TinyUSB available at E:/Github/pico-sdk/lib/tinyusb/src/portable/raspberrypi/rp2040; adding USB support.
[cmake] Compiling TinyUSB with CFG_TUSB_DEBUG=1
[cmake] ELF2UF2 will need to be built
[cmake] -- Could NOT find Doxygen (missing: DOXYGEN_EXECUTABLE) 
[cmake] -- Configuring done
[cmake] -- Generating done
[cmake] -- Build files have been written to: E:/Github/pico-sdk/build

[kilograham]

Ah, well -DPICO_TOOLCHAIN_PATH:STRING=... wasn't something i was even aware of, and is the reason for the difference in behavior.

Can you check

set(PICO_TOOLCHAIN_PATH "${PICO_TOOLCHAIN_PATH}" CACHE INTERNAL "")

works for you

[josesimoes]

Yes, that works.

🤔 I didn't think of adding the " because, from the comment, I was under the impression that the intent of the line was precisely to clear the variable.

[josesimoes]

I can still submit the PR with your fix, if you want to. Not sure if you prefer to handle this other way...
Just let me know.

[kilograham]

sure, thx