With lld, that single-file rebuild+relink drops from 1.6 seconds (with gold) to 1.2 seconds. lld spits out a bunch of warnings that neither ld nor gold cared a

With lld, that single-file rebuild+relink drops from 1.6 seconds (with gold) to 1.2 seconds. lld spits out a bunch of warnings that neither ld nor gold cared about, about finding local symbols in the global symbol table of some of the third-party .so libraries I link against. Not sure to what extent I should care about that; the final build product does run the same as always. And just so that nobody else needs to go searching; looks like ccache added support for split dwarf debugging data in its version 3.2.3, about three years ago. (although I haven't actually tried it to confirm, yet)