@meteorcloudy We found this workaround to fix the issue while still using the latest MSVC version: actions/runner-images#10004 (comment)

Oh, do you mean adding /D_DISABLE_CONSTEXPR_MUTEX_CONSTRUCTOR? That would only work for Bazel binaries having this change? Otherwise, we still need to ask users to upgrade vcruntime140.dll, right?

I'm hoping Microsoft could release a new MSVC version that fixes this issue.. otherwise, we'll have to give people a heads-up before switching to the latest MSVC (maybe in Bazel 8).

Oh, do you mean adding /D_DISABLE_CONSTEXPR_MUTEX_CONSTRUCTOR? That would only work for Bazel binaries having this change? Otherwise, we still need to ask users to upgrade vcruntime140.dll, right?

Yes. For building Bazel we would only need to add the copt, for Bazel itself we either need to add this to the toolchain or have users deal with the fallout themselves.

We noticed this because our protoc built from source would fail during the build.

Okay, I'll wait a bit on actions/runner-images#10004 to see if there is any official recommended solution. In general, we probably shouldn't add too many random options in the default toolchain.