Warning: Path is not a file: AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\bin\gcc, despite IntelliSense working

[fefrei]

Type: LanguageService

Describe the bug

• OS and Version: Windows 10 1903
• VS Code Version: 1.35.1
• C/C++ Extension Version: 0.23.1
• Other extensions you installed (and if the issue persists after disabling them): None

I'm getting this warning when trying to set "compilerPath": "/usr/bin/gcc":

Path is not a file: "C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\bin\gcc".

The warning is actually incorrect: This file exists, and IntelliSense works fine. If I remove "compilerPath": "/usr/bin/gcc" from my configuration, IntelliSense no longer works, and I get build errors, so the configuration is used despite this warning.

To Reproduce

I'm pretty sure these steps don't suffice, but here's what I did:

1. Install Ubuntu through WSL.
2. Create this c_cpp_properties.json:

   {
       "configurations": [
           {
               "name": "tool",
               "defines": [],
               "compilerPath": "/usr/bin/gcc",
               "cStandard": "c11",
               "cppStandard": "c++17",
               "intelliSenseMode": "gcc-x64"
           }
       ],
       "version": 4
   }
   

That's it.

Screenshots

[sean-mcmanus]

I don't repro this problem, with Ubuntu or Ubuntu 18.04. The only way I was able to repro it was when I did not have gcc installed. Can you run the C/C++: Log Diagnostics command to see what gcc path it is using when you use the "/usr/bin/gcc"?

[fefrei]

This is the output (with a configuration that also has some includePath entries, previously omitted because the problem happened without them):

-------- Diagnostics - 2019-6-25 23:10:13
Version: 0.23.1
Translation Unit Mappings:
[C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\ForwardVerifier.cpp]:
    C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\ForwardVerifier.cpp
    C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\Chunk.h
    C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\ForwardVerifier.h
    C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include\c++\7\stdexcept
[C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\PendulumVerifier.cpp]:
    C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\PendulumVerifier.cpp
    C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\Chunk.h
    C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\ForwardVerifier.h
    C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include\c++\7\stdexcept
    C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\PendulumVerifier.h
Translation Unit Configurations:
[C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\ForwardVerifier.cpp]:
    Process ID: 2376
    Memory Usage: 82 MB
    Compiler Path: /usr/bin/gcc
    Includes:
        C:\Users\felix\git\hypro\src
        C:\Users\felix\git\hypro\src\hypro
        C:\Users\felix\git\hypro\build\resources\src\glpk_download\include
        C:\Users\felix\git\carl\src
        C:\Users\felix\git\carl\build\resources\include
        C:\Users\felix\git\carl\build\resources\src\CoCoALib-EP\include
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include\c++\7
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include\x86_64-linux-gnu\c++\7
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include\c++\7\backward
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\lib\gcc\x86_64-linux-gnu\7\include
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\local\include
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\lib\gcc\x86_64-linux-gnu\7\include-fixed
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include\x86_64-linux-gnu
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include
    Standard Version: c++17
    IntelliSense Mode: gcc-x64
    Other Flags:
        --g++
        --gnu_version=70400
[C:\Users\felix\git\draisine-hypro\tool\src\lib\verifier\PendulumVerifier.cpp]:
    Process ID: 8528
    Memory Usage: 40 MB
    Compiler Path: /usr/bin/gcc
    Includes:
        C:\Users\felix\git\hypro\src
        C:\Users\felix\git\hypro\src\hypro
        C:\Users\felix\git\hypro\build\resources\src\glpk_download\include
        C:\Users\felix\git\carl\src
        C:\Users\felix\git\carl\build\resources\include
        C:\Users\felix\git\carl\build\resources\src\CoCoALib-EP\include
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include\c++\7
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include\x86_64-linux-gnu\c++\7
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include\c++\7\backward
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\lib\gcc\x86_64-linux-gnu\7\include
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\local\include
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\lib\gcc\x86_64-linux-gnu\7\include-fixed
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include\x86_64-linux-gnu
        C:\Users\felix\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\usr\include
    Standard Version: c++17
    IntelliSense Mode: gcc-x64
    Other Flags:
        --g++
        --gnu_version=70400
Total Memory Usage: 122 MB

[sean-mcmanus]

That output looks correct. Hmm, not sure why the config squiggle would appear, but you could get the incorrect squiggle to go away via "enableConfigurationSquiggles": false in the root (or the matching C_Cpp.default.enableConfigurationSquiggles setting).

@michelleangela @Colengms Any ideas how this incorrect squiggle could occur or are you able to repro it?

[fefrei]

While I don't know the internals, I find it really suspicious that I configure /usr/bin/gcc, and the debug output lists /usr/bin/gcc, but the squiggle complains about the Windows version of that path.

[sean-mcmanus]

The code that implements this squiggle is in our open source TypeScript, so theoretically you could debug it to see why it's failing for you if you use the "release" branch. The code runs on Windows so we need to convert the path to the Windows path, which appears to work successfully, so I don't know why it would fail to be found.

[fefrei]

Hm, OK. Another thought: While the file does exist, it's a 0-byte file, because it's a symbolic link on the Linux side. Maybe this is tripping something up?

[sean-mcmanus]

That should still work. It's a symbolic link to gcc-7 for me as well. The only case it would fail is if there was a symbolic link in the WSL version of the path that we would need to translate on the WSL side in order to get the correct Windows path. Your OS matches mine as well, so I don't know what is different that could be causing the failure.

[sean-mcmanus]

Oh, wait, it shouldn't be 0 bytes -- are you sure it's really 0 bytes? Size on Disk can be 0 bytes, but it should contain text when opened in notepad (i.e. Size not 0).