This skips bumping Windows sccache because we run into compilation failures when
doing so (-m32 not supported by clang-cl?). Not clear on cause, but seems
easiest to just hold back.
This should avoid PGO-related failures encountered on Linux, and more broadly
seems like a good idea on other platforms as well (though it is likely not
necessary right this moment).
Currently mirrors are stored in the rust-lang-ci2 S3 bucket along with
CI toolchains. This is problematic for multiple reasons:
- CI IAM credentials are allowed to both edit and delete those files.
A malicious user gaining access to those credentials would be able to
change our mirrored dependencies, possibly backdooring the compiler.
- Contents of the rust-lang-ci2 bucket are disposable except for the
mirrors' content. When we implement backups for S3 buckets we'd have
to replicate just that part of the bucket, complicating the backup
logic and increasing the chance of mistakes. A standalone bucket will
be way easier to backup.
This commit switches our CI to use the new rust-lang-ci-mirrors bucket.
Ideally I'd like to soon enable sccache for rustbuild itself and some of the
stage0 tools, but for that to work we'll need some better Rust support than the
pretty old version we were previously using!
Moving buckets from us-east-1 to us-west-1 because us-west-1 is where
rust-central-station itself runs and in general is where we have all our other
buckets.
Use the `-f` flag to indicate that, for example, a 500 response code is to be
considered a failure, triggering the normal retry logic. Also ignore errors
where we check the date from google.com, as a failure there shouldn't fail the
build.
