Comment by tavianator

Just tried reconfiguring LLVM:

    27.24s user 8.71s system 99% cpu 36.218 total

Admittedly the LLVM build time dwarfs the configuration time, but still. If you're only building a smaller component then the config time dominates:

    ninja libc  268.82s user 26.16s system 3246% cpu 9.086 total