Compiling on network share using relative paths fails

I think this is a bug…but it’s so big that I can’t believe I’m the first person to find it. Perhaps someone can help me find a workaround…

I discovered that clang++ will not find a source file if it is located on a network share (if using a relative path). For example, I have place the same file “main.cpp” into C:\temp (a local drive) and T:\temp (a network SMB share).

If I change pwd to C:\temp the following line works:

C:\android\cmdline-tools\ndk\21.1.6352462/toolchains/llvm/prebuilt/windows-x86_64/bin/clang++ main.cpp

but if I change pwd to T:\temp the above line does NOT work (can’t find file). However, if I specify the full path for the source file for clang++ T:\temp\main.cpp then it works.

Since my make files are generated (using qmake) I have no control over the paths passed to clang++. Can someone explain why clang++ can’t find source files on network shares (using relative paths), and how to fix this?

In case it matters, I’m running on Win10 64 bit. I’ve tried putting source files on an SMB share, and a NFS share…and the results are the same.

Can you confirm other tools given similar path specifications in similar circumstances (command line/current working directory/etc) succeed where clang fails? (MSVC, notepad, gcc, ‘cat’ (if Windows has a ‘cat’))

Yes – I can open the file using relative path (in notepad) or type (cat) the file from the command line. Only clang++ seems to have a problem.

Can you please paste the error message (or the full output) here?

You could try to use some strace-like tool to see what files is clang trying to open. I'm not familiar with Windows but maybe you could use this:
https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/logger-and-logviewer

Jan