1968057 - Linux ASAN and TSAN jobs don't support Rust 1.82.0's &raw operators

Status: NEW

(Firefox Build System :: Toolchains, defect)

Description

[Max Inden]

• Firefox's minimal Rust version is 1.82.0.
• Rust 1.82.0 stabilized &raw const and &raw mut operators (RFC 2582).
• Firefox's QUIC implementation - Neqo - uses these new operators in Neqo 0.13.3.
• Updating https://github.com/mozilla-firefox/firefox to Neqo 0.13.3 fails in build-linux64-asan/opt and build-linux64-tsan/opt job with the following error message:

  error[E0658]: raw address of syntax is experimental
  

  https://treeherder.mozilla.org/jobs?repo=try&revision=b7905ac4e2900df6c5c493011be71dd7342865a1&selectedTaskRun=GFayRWAqSnaQz0hF5gDceA.0
• My suspicion is, that this is due to both of these jobs using rustc version... 1.82.0-dev instead of standard 1.82.0.

Is the above correct? What would be the best next step?

Comment 1

[Mike Hommey [:glandium]]

The version of rust we use for tsan/asan builds dates from during the 1.82.0 development period because some changed in rustc 1.82 broke our patches that make -Zbuild-std=std work alongside vendored crates. So that version of rust can lack a few things that normal 1.82.0 has.
See bug 1956123, bug 1957042, bug 1952126 for similar problems we've faced in the past and how they were addressed. The relevant change from rustc 1.82.0 that is missing is https://github.com/rust-lang/rust/pull/127679.

Comment 2

[Max Inden]

Thank you for the pointers.

Given that our change to &raw is a syntactic change only, I don't think it is worth carrying a patch to our Rust 1.82.0-dev fork for it. Thus I am proposing to revert the change on the Neqo side in https://github.com/mozilla/neqo/pull/2660.

Comment 3

[Max Inden]

For the record https://github.com/mozilla/neqo/pull/2660 landed as part of Bug 1966980.

In addition we reverted all MSRV-1.82.0 changes in Neqo as part of https://github.com/mozilla/neqo/pull/2661.

We will keep our MSRV at Rust 1.81.0 until all Firefox CI workflows use 1.82.0.