v3.0.6 introduced dependency on zstdmt (not just zstd) for cache creation, fails on Windows

As of v3.0.6 this apparently requires zstdmt, not just zstd, which is a major departure. I have not found any Windows binaries for zstdmt. I’m not sure it’s available elsewhere either.

This is what happens:

##[debug]Archive Path: C:\drud-actions-runner\_work\_temp\ff5371eb-5f15-4474-8084-5df62fc397fa\cache.tzst "C:\Program Files\Git\usr\bin\tar.exe" --posix --use-compress-program zstdmt -cf cache.tzst --exclude cache.tzst -P -C C:/drud-actions-runner/_work/ddev/ddev --files-from manifest.txt --force-local /bin/sh: zstdmt: command not found /usr/bin/tar: cache.tzst: Cannot write: Broken pipe

It was already hard enough to get zstd onto Windows… It’s sad to break things now by changing the tar compression format even father.

Previous instructions for getting zstd into a Windows machine were at https://github.com/actions/cache/issues/580#issuecomment-1165839728

[kleisauke]

I can confirm that v3.0.8 fixes the issue, see e.g. commit https://github.com/kleisauke/wasm-vips/commit/50c7d00b8e22986a096aab8c55737bfca245c1b8.

[pdotl]

Hi @rfay, the tar compression(zstd) on Windows while using the above workaround should now work. Please test and let us know if the issue is now resolved.