Re: On CI

There are some good ideas here, but I want to throw out another one: put all our effort into reducing compile times. There is a loud plea to do this on Discourse , and it would both solve these CI problems and

Re: On CI

Recompilation avoidance I think in order to cache more in CI, we first have to invest some time in fixing recompilation avoidance in our bootstrapped build system. I just tested on a hadrian perf ticky build: Adding one line of *comment* in the compiler causes - a (pretty slow, yet

Re: On CI

Doing "optimistic caching" like you suggest sounds very promising. A way to regain more robustness would be as follows. If the build fails while building the libraries or the stage2 compiler, this might be a false negative due to the optimistic caching. Therefore, evict the "optimistic caches"

RE: On CI

Simon Peyton Jones via ghc-devs writes: >> 1. Building and testing happen together. When tests failure >> spuriously, we also have to rebuild GHC in addition to re-running >> the tests. That's pure waste. >> https://gitlab.haskell.org/ghc/ghc/-/issues/13897 tracks this more >> or less.

RE: On CI

1. Building and testing happen together. When tests failure spuriously, we also have to rebuild GHC in addition to re-running the tests. That's pure waste.