Incremental compilation warning "Error finalizing incremental compilation session directory" when building compiler on Windows

[rylev]

When building the compiler on Windows with incremental turned on I often get the following warning:

warning: Error finalizing incremental compilation session directory `\\?\C:\Users\ryanl\Code\rust\build\x86_64-pc-windows-msvc\stage0-rustc\x86_64-pc-windows-msvc\release\incremental\rustc_incremental-3eitboxu59x4j\s-g08srunmh1-1cw7crv-working`: Access is denied. (os error 5)

Compilation continues after this and leads to a successful build.

A similar issue has been reported before (#48700), but that is a panic during compilation of a normal crate.

[ChrisDenton]

Seems to be an fs::rename operation failing? The likely cause would be a file handle that is still open.

[Spidy104]

when will this bug be removed, and will this bug, cause major problems, for creating various stuff, cuz I am new to rust, and I continuously get this error message!

[strottos]

I get this error a lot having just moved to a Windows PC. Whilst everything clearly compiles and runs fine it's very frustrating and can cause real problems. For example, I ran cargo test under the latest tokio and tests fail as such:

ACTUAL OUTPUT:
┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈
warning: Error finalizing incremental compilation session directory `\\?\$WORKSPACE\target\tests\target\debug\incremental\build_script_build-1pup4b7wjll7v\s-g2b8bzyb6c-xy1e9r-working`: Access is denied. (os error 5)

<actual expected output>

Elsewhere I've seen it reported as a VS Code or WSL problem and seen fixes like this proposed: #62031 (comment)
However I'm working entirely without VS Code or WSL and just running cargo build or whatever through Powershell in Windows Terminal.

[ZimCodes]

I have also received this warning as well. The solution for me was to run cargo clean and then run cargo check (as I wanted to check for more warnings/errors). From here everything was all green.

[joelswenddal]

I have also received this warning as well. The solution for me was to run cargo clean and then run cargo check (as I wanted to check for more warnings/errors). From here everything was all green.

This resolved it for me as well, moving to wsl 1 on Windows PC. Thanks!

[michaelwoerister]

I'll try to take a look at this.

[michaelwoerister]

I haven't seen any reports about this after #95304 was merged. Closing.