Still trying to find out how/when/why we lost the ability to parallel build...

Still trying to find out how/when/why we lost the ability to parallel build...

how does this manifest?

My NixOS config uses 12 cores by default, and from the moment I started building the PR I'm getting errors like

/nix/store/8x3b9g3hjyw1fdkfry01yhp8lkccnfi7-x86_64-w64-mingw32-binutils-2.38/bin/x86_64-w64-mingw32-dlltool: dlls/iphlpapi/libiphlpapi.delay.a: error reading iphlpapi_dll_s00001.o: No such file or directory
winebuild: /nix/store/8x3b9g3hjyw1fdkfry01yhp8lkccnfi7-x86_64-w64-mingw32-binutils-2.38/bin/x86_64-w64-mingw32-dlltool failed with status 1
make: *** [Makefile:96346: dlls/iphlpapi/libiphlpapi.delay.a] Error 1
make: *** Waiting for unfinished jobs....
/nix/store/8x3b9g3hjyw1fdkfry01yhp8lkccnfi7-x86_64-w64-mingw32-binutils-2.38/bin/x86_64-w64-mingw32-dlltool: dlls/iphlpapi/libiphlpapi.cross.a: error reading iphlpapi_dll_t.o: No such file or directory
winebuild: /nix/store/8x3b9g3hjyw1fdkfry01yhp8lkccnfi7-x86_64-w64-mingw32-binutils-2.38/bin/x86_64-w64-mingw32-dlltool failed with status 1
make: *** [Makefile:96346: dlls/iphlpapi/libiphlpapi.cross.a] Error 1

When I build wine 7.4 off its original commit dd6c709 I see no such problem (35619ce is still okay as well). But on current master (without this PR) I do get it. It's been a huge pain trying to bisect the problem because of the long compile times.

Setting enableParallelBuilding = false; makes it go away, but that will make rebuilding the wine variants take way too much time.

Just tested this and it's working fine for me (better indeed than 7.4 since a few of my applications stopped working with it).

I would suggest merging this, since it's better to have a version that compiles slowly than not at all.

And investigate the parallel building issue separately.

I can remove the draft status if people want, but I probably won't run the full nixpkgs-review on it since that will now trigger so many serialized builds...

Would be nice to get #172617 first, then we can probably keep parallel builds enabled.

Result of nixpkgs-review pr 170943 run on x86_64-linux 1

Built this using only 2 cores per build, that seems to sidestep the dlltool issue sufficiently.

I'd like to test/review it as is, but honestly I don't know how to reduce the count of build-cores.

I tried something like:

NIX_BUILD_CORES=1 nix build -j 1 .#wineWowPackages.staging

But that's not working...

Regardless of that, I would suggest setting enableParallelBuilding = false so that no-one else runs into this issue, and set it back to true in this PR: #172617

I took out the big hammer and set my nix.settings.cores to 2 on my NixOS system for the occasion.

Since hydra was still happy building wine until now I figured I'd leave the enableParallelBuilding alone because the build should end up in the binary cache soon, but I can go either way.