Policy: rustc can be run on case-insensitive filesystems but works in a case-sensitive way

[jieyouxu]

Proposal

rustc can be run on case-insensitive filesystems, but works in a case-sensitive way in terms of filesystem handling. That is, we don't want to guarantee support for rustc to work in a case-insensitive way as T-compiler does not want to maintain support for rustc to work in a case-insensitive way and take on the additional maintenance burden.

The general idea is that

I think there's a small distinction between "should we look for target specs without a mandatory extension" and "full support for case insensitivity" - I'm inclined to say no for the latter and yes for the former.

— https://rust-lang.zulipchat.com/#narrow/channel/238009-t-compiler.2Fmeetings/topic/.5Bweekly.5D.202024-12-12/near/488664418

Mentors or Reviewers

T-compiler as a whole.

Process

The main points of the Major Change Process are as follows:

• File an issue describing the proposal.
• A compiler team member or contributor who is knowledgeable in the area can second by writing @rustbot second.
  • Finding a "second" suffices for internal changes. If however, you are proposing a new public-facing feature, such as a -C flag, then full team check-off is required.
  • Compiler team members can initiate a check-off via @rfcbot fcp merge on either the MCP or the PR.
• Once an MCP is seconded, the Final Comment Period begins. If no objections are raised after 10 days, the MCP is considered approved.

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.

[rustbot]

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.

Concerns or objections to the proposal should be discussed on Zulip and formally registered here by adding a comment with the following syntax:

@rfcbot concern reason-for-concern 
<description of the concern> 

Concerns can be lifted with:

@rfcbot resolve reason-for-concern 

See documentation at https://forge.rust-lang.org

cc @rust-lang/compiler

[wesleywiser]

@rustbot second