I think that jump was due to lto (link time optimsation) getting activated by default for Firefox on Gentoo around that time. It looked very strange at first, b

I think that jump was due to lto (link time optimsation) getting activated by default for Firefox on Gentoo around that time. It looked very strange at first, because the build log just pauses while the lto passes hog a lot of cpu and memory for 20min or so. Rust has been in Firefox for about 5 years now, I think.