backtrace tests: support more ways of checking out Rust locally
Tests failed when using a local build as my folders are called `rustc`, `rustc.2`, ...
Expand the regex to also support that naming scheme.
disable debug assertions in the standard library
Debug assertions in the standard library can be somewhat expensive to check, in particular the ones covering each and every `ptr::write/copy/copy_nonoverlapping`. Miri will find most of those problems anyway since they cause UB. There are other debug assertions, such as ensuring internal invariants are maintained, but given how slow Miri already is, I think it is better to skip those checks in Miri and instead figure out a better way for people to use a standard library with debug assertions enabled.
test Box::into_raw aliasing
Directly test aliasing problems caused by `Box::into_raw` issues (like we have them again right now due to https://github.com/rust-lang/rust/pull/77187, but the pinned rustc is older than that so this should still be able to land).
Hide readlink error in `./miri`
Fixes#1597.
`./miri` is just testing whether the platform supports `readlink -e`,
but it didn't hide properly hide the stderr output. This fixes that.
Don't force-install xargo
Previously miri used `cargo install xargo -f` which shouldn't be
necessary anymore since `cargo install` will now upgrade without `-f`.
The only reason I can see to use `-f` is from the cargo docs:
> This is also useful if something has changed on the system that you
> want to rebuild with, such as a newer version of `rustc`.
See the [discussion on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/why.20does.20miri.20require.20xargo/near/214351239).
Enable `backtrace` feature in the generated `Xargo.toml`
This allows the normal std panic hook to print a backtrace if
`RUST_BACKTRACE=1` and `-Z miri-disable-isolation` are set
build: Gate only on GHA: remove travis and appveyor ci config
It's been over a week since #1571 merged.
The GHA evaluation is successful.
This PR removes CI config of travis and appveyor.
Now MIRI gates on github actions CI only.
Will need <https://github.com/rust-lang/homu/pull/109> to merge first,
otherwise bors will stuck.
Also, one may need to remove `continuous-integration/appveyor/pr` CI checks
in repo settings or appeveyor website.
