'debug-opt' builds are timing out while building librustc

[michaelwoerister]

See
https://buildbot.rust-lang.org/builders/auto-linux-64-debug-opt/builds/3453
https://buildbot.rust-lang.org/builders/auto-linux-64-debug-opt/builds/3454
https://buildbot.rust-lang.org/builders/auto-linux-64-debug-opt/builds/3455
and probably a few more.

[brson]

Can this crate legitimately be taking 30 minutes to build? http://perf.rust-lang.org/ says bootstrap time has gotten ... 92% better. wtf

[Mark-Simulacrum]

Well, the new numbers show only 0.1% decrease, I suspect that the 92% was noise from the LLVM problems.

[eddyb]

@brson I have tried debug-opt locally and there's no such large measurable time difference, although rustbuild may have different behavior here.

[alexcrichton]

Haven't seen these in awhile, increase in timeout seems to have fixed it.