Require users to confirm they know RUSTC_BOOTSTRAP is unsupported before using it #350
Closed
1 of 3 tasks
Labels
major-change
A proposal to make a major change to rustc
T-compiler
Add this label so rfcbot knows to poll the compiler team
Proposal
Currently, the way to break all stability guarantees in the compiler is to set an environment variable:
RUSTC_BOOTSTRAP=1
. While the release team recommends against this in https://rustc-dev-guide.rust-lang.org/building/bootstrapping.html#complications-of-bootstrapping and various other places, it's easy to see it in forums or discussions and use it without knowing that it's not meant to be used outside of bootstrapping. Additionally, it looks very similar to other benign things, like settingRUST_BACKTRACE=1
.I propose to change the name of
RUSTC_BOOTSTRAP
toRUSTC_UNSTABLE_ON_STABLE
. The intention is not to obfuscate the text, but to make sure the user is making a conscious decision to break stability guarantees instead of copy/pasting from somewhere they saw it online.For more discussion, see around https://rust-lang.zulipchat.com/#narrow/stream/122651-general/topic/how.20does.20release.20branching.20work.3F/near/208059954.
Some proposed alternative names:
RUSTC_FORCE_UNSTABLE
RUSTC_UNSTABLE
I_OPT_OUT_OF_RUST_STABILITY_GUARANTEES_AND_CANNOT_COMPLAIN_ABOUT_IT
RUSTC_BOOTSTRAP="I understand that unstable features are unstable and may break at any time"
Mentors or Reviewers
@joshtriplett for gathering consensus on the change
@Mark-Simulacrum for the implementation (which should be fairly simple)
Process
The main points of the Major Change Process is as follows:
@rustbot second
.-C flag
, then full team check-off is required.@rfcbot fcp merge
on either the MCP or the PR.You can read more about Major Change Proposals on forge.
Comments
This issue is not meant to be used for technical discussion. There is a Zulip stream for that. Use this issue to leave procedural comments, such as volunteering to review, indicating that you second the proposal (or third, etc), or raising a concern that you would like to be addressed.
The text was updated successfully, but these errors were encountered: