There are releases at https://github.com/rust-lang/rust but do NOT use those to try to bootstrap - the tarballs are much smaller, various essential parts are missing. The only real benefit of looking at releases there is that it's possible to see the versions.
The source needs to be downloaded from https://static.rust-lang.org/dist/ as rustc-<VERSION>-src.tar.gz : this site is NOT searchable.
rustc-1.41.1 and 1.42.0
There were problems with rustc-1.41.0, one of which involved errors in borrow checking - it should not be used. There was also a problem which can apparently lead to a segmentation fault. These are fixed in 1.41.1, but the fix for one of these (issue 69225) required them to backport an LLVM change to their shipped version.
If you build rustc-1.41.1 with system llvm-9.0.1 the new test will fail:
That is bad.
Similarly, rustc-1.42.0 needs to be built with its shipped llvm unless the system version is llvm-10.
Building with the shipped llvm
This should always be reliable, but the build is a lot slower than with system llvm.
The changes in config.toml to use shipped llvm are:
- Comment out link-shared = true
- Remove the [target-...] sections with their pointers to llvm-config.