bug: Build::is_flag_supported `/std:c++17` returns false on 1.2.1 ->1.2.5 transition (on x86_64-pc-windows-msvc)

[dj8yfo]

This is suppossedly a bug of https://docs.rs/cc/1.2.5/cc/struct.Build.html#method.is_flag_supported

on x86_64-pc-windows-msvc.

After applying diff near/cargo-near@4a4a772
, running build script in https://github.com/brson/wasm-opt-rs/blob/8854bd8a58d7393c7bacd950884aea521ce8e19f/components/wasm-opt-sys/build.rs#L365
fails https://github.com/near/cargo-near/actions/runs/12417889777/job/34669855813

Pinning cc to 1.2.1 in near/cargo-near#282 helps (build succeeds on the identical image)

[NobodyXu]

@dj8yfo I suspect it's because of f770d56

can you try forking cc and comment out that changes, and see if it fixes the problem for you please?

[BD103]

Hi! We've also managed to reproduce this when running the build script for wasm-opt-sys v0.166.0 in TheBevyFlock/bevy_cli#199. The exact error was caught by our CI in this run (Archived version).

I don't have a Windows computer anymore, so I can't reproduce this locally, but let me know if there's anything else I can do to help!

[CryZe]

This reproduces with cc 1.2.5, not with 1.2.4, which bisects the bug down to: #1322

[ChrisDenton]

I think this was caused by #1322 which removed the -c flag (i.e. don't invoke the linker). EDIT: ah ninja'd

It complains about msvcrt.lib not being found. Either we need to supply the lib path or else do something like:

cmd.args(["/link", "/entry:main"]);

To avoid depending on the C runtime libraries.