Comment # 10 on bug 1133254 from Aaron Puchert

We're actually using ThinLTO now for the second stage on most architectures, so
I think we can close this.

(In reply to Aaron Puchert from comment #5)
> I'm not sure if the "lamb" machines all have the same hardware, but the
> current build in devel:tools:compiler takes ~10000s, while with ThinLTO it
> takes ~15000s. I should compare the build times on the same machine though
> to be sure.

As it turns out, the problem is that we enable malloc-checking for builds,
which introduces a global lock for allocations. That is a problem for ThinLTO
which works by having multiple threads in the same linker process. When turning
that off via "unset MALLOC_CHECK_", the ThinLTO-enabled build is not
significantly slower than a regular build.