[sanxiyn]

While I think n>1000 data points on Rust learning curve is informative, I think build time complaint is less so.

This being Google, it probably means something like "this C++ build takes 24 hours locally, but thanks to magical distributed build infrastructure it completes in 10 minutes, whereas Rust build takes 18 hours locally but even with magic does not complete in under 30 minutes, which is too long". That is important to Google, but it is almost completely irrelevant to anyone outside Google.

It is unclear to me whether improving rustc performance is the right solution to Google's problem. It is probable working on Rust integration to Google's build infrastructure is higher ROI than working on rustc.