If you’re seeing weird build failures in memory or string functions, rebase past the time of this message and you should be working again! =) More on why follows:
Sometime in the last few days, it appears that Github / Azure have upgraded the machines used for GitHub Actions. Because our builds defaulted for -march=native by default, memory and string routines will use more performant instructions available on the newer chips.
At the same time, our builders use sccache to conserve compute and to reduce build cycle time on most of the bots.
The two of these together meant that we were delightfully replaying object files that couldn’t be run on some of the machines, based entirely on which machines populated the cache.
Several of us were involved in the fixes, and I want to pass on my thanks to many folks who were up early and late for brainstorming and reviews: @petrhosek, @michaelrj-google, @lntue, @boomanaiden154-1 (my apologies if I’ve missed someone!)
There were a number of PRs that went into this, from temporary fixes, to fixing the build without -march=native (it turns out that no one was testing or running the SSE2 build…), and then reseting the cache.
We expect that the presubmit and postsubmit bots should now be happier. If anything weird happens over the weekend, feel free to message me on Discord!
Tks,
Jeff Bailey