typespeed: fix darwin compatibility

[nicknovitski]

Motivation for this change

I use nix on OS X, and I like the game.

Things done

• Tested using sandboxing
  (nix.useSandbox on NixOS,
  or option build-use-sandbox in nix.conf
  on non-NixOS)
• Built on platform(s)
  • NixOS
  • OS X
  • Linux
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

[mention-bot]

By analyzing the blame information on this pull request, we identified @auntieNeo, @dezgeg and @pSub to be potential reviewers

[nicknovitski]

Huh, that's strange. I built it successfully on OS X and NixOS before opening the PR. Maybe I had something wrong with my environment?

[dezgeg]

Can you try if a simple CC=cc works on both? I think it should...

[nicknovitski]

Huh! I hadn't thought of that, and I will try it.

[nicknovitski]

Well, it definitely works on OS X!

[dezgeg]

Ok, great!

[dezgeg]

@domenkozar Travis on Linux is still broken from around the time it was last touched by adding the Darwin support. (Looks like /tmp is now noexec or something). Please investigate.

[domenkozar]

@dezgeg thanks I'll ask travis team. No change was made on our side regarding this.

[domenkozar]

Let's experiment on #16022