Long git directory name causes error C1083 when building coreclr tests (cl.exe)

[steveharter]

Having a long directory name causes issues when building the coreclr tests. I verified that long paths are enabled in both git and the registry.

Repro (Windows x64)

• Create a long directory name such as C:\git\ThisIsSomewhatOfaLongName
• Clone runtime repo into that
• build -s clr+libs (this works)
• src\tests\build.cmd /p:LibrariesConfiguration=Debug (this fails with the error below)

Error:

[219/384] Building CXX object baseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\CMakeFiles\ForeignThreadRevPInvokeUnhandledNative.dir\ForeignThreadRevPInvokeUnhandledNative.cpp.obj
FAILED: baseservices/exceptions/UnhandledExceptionHandler/ForeignThreadRevPInvokeUnhandled/CMakeFiles/ForeignThreadRevPInvokeUnhandledNative.dir/ForeignThreadRevPInvokeUnhandledNative.cpp.obj
C:\PROGRA~1\MIB055~1\2022\Preview\VC\Tools\MSVC\1443~1.346\bin\Hostx64\x64\cl.exe  /nologo /TP -DForeignThreadRevPInvokeUnhandledNative_EXPORTS -DHOST_64BIT -DHOST_AMD64 -DHOST_WINDOWS -DNDEBUG -DTARGET_64BIT -DTARGET_AMD64 -DTARGET_WINDOWS -DURTBLDENV_FRIENDLY=Retail -DWINDOWS -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -IC:\git\ThisIsSomewhatOfaLongName\src\native -IC:\git\ThisIsSomewhatOfaLongName\src\tests\Common\Platform /DWIN32 /D_WINDOWS  /GR- /O2 /Ob2 /DNDEBUG -MT /GL /Ox /EHa /nologo /W4 /WX /Oi /Oy- /Gm- /Zp8 /Gy /GS /fp:precise /FC /MP /Zm200 /Zc:strictStrings /Zc:wchar_t /Zc:inline /Zc:forScope /wd4065 /wd4100 /wd4127 /wd4131 /wd4189 /wd4200 /wd4201 /wd4206 /wd4239 /wd4245 /wd4291 /wd4310 /wd4324 /wd4366 /wd4456 /wd4457 /wd4458 /wd4459 /wd4463 /wd4505 /wd4702 /wd4706 /wd4733 /wd4815 /wd4838 /wd4918 /wd4960 /wd4961 /wd5105 /wd5205 /we4007 /we4013 /we4102 /we4551 /we4640 /we4806 /we4055 /we4146 /we4242 /we4244 /we4267 /we4302 /we4308 /we4509 /we4510 /we4532 /we4533 /we4610 /we4611 /we4700 /we4701 /we4703 /we4789 /we4995 /we4996 /w34092 /w34121 /w34125 /w34130 /w34132 /w34212 /w34530 /w35038 /w44177 /Zi /ZH:SHA_256 /source-charset:utf-8 /guard:cf /guard:ehcont -wd4100 -wd4242 -wd4244 -wd4514 -wd4625 -wd4626 -wd4668 -wd4710 -wd4711 -wd4774 -wd4820 -wd5025 -wd5026 -wd5027 -wd5039 /showIncludes /Fobaseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\CMakeFiles\ForeignThreadRevPInvokeUnhandledNative.dir\ForeignThreadRevPInvokeUnhandledNative.cpp.obj /Fdbaseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\CMakeFiles\ForeignThreadRevPInvokeUnhandledNative.dir\ /FS -c C:\git\ThisIsSomewhatOfaLongName\src\tests\baseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\ForeignThreadRevPInvokeUnhandledNative.cpp
C:\git\ThisIsSomewhatOfaLongName\src\tests\baseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\ForeignThreadRevPInvokeUnhandledNative.cpp : fatal error C1083: Cannot open compiler generated file: '': Invalid argument
[240/384] Building CXX object profiler\native\CMakeFiles\Profiler.dir\rejitprofiler\rejitprofiler.cpp.obj
ninja: build stopped: subcommand failed.
BUILDTEST: Error: native test build failed.

I did not attempt to diagnose the root cause but note that the path C:\git\ThisIsSomewhatOfaLongName\src\tests\baseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\ForeignThreadRevPInvokeUnhandledNative.cpp is 169 characters, short of MAX_PATH (260).

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[huoyaoyuan]

Enabling long path support is listed under Windows requirements. Do you still encounter this error with long path enabled? It can be easily enabled with Dev Home.

[steveharter]

I do have long paths enabled:

PS C:\git\ThisIsSomewhatOfaLongPath> git config --system core.longpaths
true

PS C:\git\ThisIsSomewhatOfaLongPath> Get-ItemProperty HKLM:\SYSTEM\CurrentControlSet\Control\FileSystem -Name LongPathsEnabled
LongPathsEnabled : 1

[steveharter]

I believe cl.exe has issues with MAX_PATH even when long paths are enabled in Windows registry:
https://developercommunity.visualstudio.com/t/compiler-cant-find-source-file-in-path-/10221576
https://developercommunity.visualstudio.com/t/clexe-command-line-error-d8022-cannot-open-path-re/1478916

However, I didn't see where I was very close to MAX_PATH. Perhaps there was some artifacts\bin folders that have a longer path but not shown in the error message.

[mdh1418]

I'm starting to see this too when building runtime tests locally after rebasing on main. It seems to be related to the new test added in #109806. I'm also not sure why that test needs to be compiled if I want to just build a separate particular runtime test .\src\tests\build.cmd test <path_to_specific_runtime_test_csproj>

[mdh1418]

I ended up using subst to associate my local repo's path to a drive letter (Thanks @tommcdon for the suggestion), and was able to shorten the generated ForeignThreadRevPInvokeUnhandledNative object path to under 250 chars. (I also have long paths enabled, similar to Steve)

[tommcdon]

Another thing to try is to enable long paths in windows per
https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation?tabs=registry#enable-long-paths-in-windows-10-version-1607-and-later:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem]
"LongPathsEnabled"=dword:00000001

[steveharter]

Another thing to try is to enable long paths in windows per
https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation?tabs=registry#enable-long-paths-in-windows-10-version-1607-and-later:

Long paths are enabled locally for me and for @mdh1418.

Those instructions also say to update the app's manifest, however the app here is cl.exe and FWIW the links I added above for known issues with cl.exe mention other users who tried to update the cl.exe manifest but then got other errors.

So the root problem appears to be with cl.exe needing a proper manifest and\or it doesn't use the \\?\ prefix necessary for paths > MAX_PATH.

[kkukshtel-unity]

I'm also seeing this on windows fwiw:

[221/387] Building CXX object baseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\CMakeFiles\ForeignThreadRevPInvokeUnhandledNative.dir\ForeignThreadRevPInvokeUnhandledNative.cpp.obj
FAILED: baseservices/exceptions/UnhandledExceptionHandler/ForeignThreadRevPInvokeUnhandled/CMakeFiles/ForeignThreadRevPInvokeUnhandledNative.dir/ForeignThreadRevPInvokeUnhandledNative.cpp.obj
C:\PROGRA~1\MICROS~4\2022\COMMUN~1\VC\Tools\MSVC\1441~1.341\bin\Hostx64\x64\cl.exe  /nologo /TP -DBUILDENV_DEBUG=1 -DDEBUG -DForeignThreadRevPInvokeUnhandledNative_EXPORTS -DHOST_64BIT -DHOST_AMD64 -DHOST_WINDOWS -DTARGET_64BIT -DTARGET_AMD64 -DTARGET_WINDOWS -DURTBLDENV_FRIENDLY=Debug -DWINDOWS -D_DBG -D_DEBUG -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -ID:\UnitySrc\Workspace\runtime\src\native -ID:\UnitySrc\Workspace\runtime\src\tests\Common\Platform /DWIN32 /D_WINDOWS  /GR- /Zi /Ob0 /Od /RTC1 -MTd /Od /EHa /nologo /W4 /WX /Oi /Oy- /Gm- /Zp8 /Gy /GS /fp:precise /FC /MP /Zm200 /Zc:strictStrings /Zc:wchar_t /Zc:inline /Zc:forScope /wd4065 /wd4100 /wd4127 /wd4131 /wd4189 /wd4200 /wd4201 /wd4206 /wd4239 /wd4245 /wd4291 /wd4310 /wd4324 /wd4366 /wd4456 /wd4457 /wd4458 /wd4459 /wd4463 /wd4505 /wd4702 /wd4706 /wd4733 /wd4815 /wd4838 /wd4918 /wd4960 /wd4961 /wd5105 /wd5205 /we4007 /we4013 /we4102 /we4551 /we4640 /we4806 /we4055 /we4146 /we4242 /we4244 /we4267 /we4302 /we4308 /we4509 /we4510 /we4532 /we4533 /we4610 /we4611 /we4700 /we4701 /we4703 /we4789 /we4995 /we4996 /w34092 /w34121 /w34125 /w34130 /w34132 /w34212 /w34530 /w35038 /w44177 /Zi /ZH:SHA_256 /source-charset:utf-8 /homeparams /guard:cf /guard:ehcont -wd4100 -wd4242 -wd4244 -wd4514 -wd4625 -wd4626 -wd4668 -wd4710 -wd4711 -wd4774 -wd4820 -wd5025 -wd5026 -wd5027 -wd5039 /showIncludes /Fobaseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\CMakeFiles\ForeignThreadRevPInvokeUnhandledNative.dir\ForeignThreadRevPInvokeUnhandledNative.cpp.obj /Fdbaseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\CMakeFiles\ForeignThreadRevPInvokeUnhandledNative.dir\ /FS -c D:\UnitySrc\Workspace\runtime\src\tests\baseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\ForeignThreadRevPInvokeUnhandledNative.cpp
D:\UnitySrc\Workspace\runtime\src\tests\baseservices\exceptions\UnhandledExceptionHandler\ForeignThreadRevPInvokeUnhandled\ForeignThreadRevPInvokeUnhandledNative.cpp : fatal error C1083: Cannot open compiler generated file: '': Invalid argument
[258/387] Building CXX object profiler\native\CMakeFiles\Profiler.dir\classfactory.cpp.obj
ninja: build stopped: subcommand failed.

Setting a reg key isn't working either. I had to also use subst to shorten the path