MinGW: Linking error while building `rustc_data_structures` - ld "cannot find -lsynchronization"

[petrochenkov]

ping @Zoxc probably

Haven't investigated this myself yet, just posting here in case there's a known fix.

[Zoxc]

Do you have a log? How did you produce this?

[retep998]

Are you getting this error while building Rust itself? If so, your MinGW installation is missing libsynchronization.a.

[petrochenkov]

Ok, libsynchronization.a is indeed a part of mingw-w64 toolchain, but it's a relatively new part that first appeared in 6.3.0, but I use 6.2.0 due to gdb bugs in newer versions.

It looks like parking_lot depends on this library (through WaitOnAddress), and rustc_data_structures now depends on parking_lot thus bumping version requirement for mingw-w64 toolchain to 6.3.0.

I guess I'll have to do what our CI does and use newer toolchain with gdb replaced with older version.