fix(git): make checkout names independent of git config by weihanglo · Pull Request #17289 · rust-lang/cargo

weihanglo · 2026-07-31T18:04:34Z

What does this PR try to resolve?

Previously the length followed user's core.abbrev.
Cargo cache layout should be stable and independent from user settings,
hence this fix.

Downside of this is that if people already had a system/user-wide
git config core.abbrev set to number other than 7,
it may lead to re-downloads.

How to test and review this PR?

Commit by commit.

This was found during -Ztrim-paths implementation,
which we would like to embed revision in the remapped object files,
and we want it to be stable.
(but probably we don't need to embed)

Previously the length followed user's `core.abbrev`. Cargo cache layout should be stable and independent from user settings. Downside of this is that if people already had a system/user-wide git config `core.abbrev` set to number other than 7, it may lead to re-downloads. This was found during `-Ztrim-paths` implementation, which we would like to embed revision in the remapped object files, and we want it to be stable.

Cargo now computes the abbreviation itself and already holds a `String`. The newtype is no longer needed.

rustbot · 2026-07-31T18:04:39Z

r? @epage

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Owners of files modified in this PR: @epage, @weihanglo
@epage, @weihanglo expanded to epage, weihanglo

weihanglo · 2026-07-31T18:05:54Z

+    ///
+    /// Like [`git2::Object::short_id`]
+    /// but ignores the user's `core.abbrev` git config.
+    pub fn to_short_id(&self, rev: git2::Oid) -> CargoResult<String> {


Have considered adding core.abbrev to our git database's config, though I don't feel comfortable with it. Git repo might be open and cloned elsewhere and we forget to set the config.

View changes since the review

Update cargo submodule 21 commits in 7c83d4cc0953b81d823e47d640c64da9b8bd4fac..c79e8f89441b3e73d6d65d125c0c745792808c74 2026-07-29 21:34:53 +0000 to 2026-08-04 19:17:33 +0000 - fix(diag): Ensure diagnostic titles work without snippets (rust-lang/cargo#17304) - refactor: Remove unnecessary mut in sources (rust-lang/cargo#17305) - feat(trim-paths): emit unremap files for final artifacts (rust-lang/cargo#17303) - fix: prevent panic when `package.build` is empty (rust-lang/cargo#17268) - Add a suggestion when adding `[lints]` to a workspace to use `[workspace.lints]` instead (rust-lang/cargo#17300) - chore(deps): update embarkstudios/cargo-deny-action action to v2.1.1 (rust-lang/cargo#17291) - refactor: move sysroot lookup to GlobalContext (rust-lang/cargo#17276) - fix(trim-paths): unambiguous and reversible remap rules (rust-lang/cargo#17302) - Avoid parsing unchanged lockfiles (rust-lang/cargo#17301) - Remove unnecessary to_path_buf (rust-lang/cargo#17295) - chore(deps): update cargo-semver-checks to v0.50.0 (rust-lang/cargo#17297) - chore(deps): update actions/checkout action to v6.1.0 (rust-lang/cargo#17290) - Remove unnecessary return at end of functions (rust-lang/cargo#17292) - make __CARGO_TEST_FORCE_ARGFILE available in distributed builds (rust-lang/cargo#17293) - Fix manual_readme lint for lower-priority README files (rust-lang/cargo#17208) - fix(git): make checkout names independent of git config (rust-lang/cargo#17289) - fix(diag): Rename redundant_readme to manual_readme (rust-lang/cargo#17288) - Remove redundant double call .to_string() (rust-lang/cargo#17286) - fix(completions): complete paths for cargo run arguments (rust-lang/cargo#17284) - test(git): exercise multi git revision lockfile (rust-lang/cargo#17279) - add context to lints documentation (rust-lang/cargo#17273) r? ghost

weihanglo added 3 commits July 31, 2026 13:43

test(git): capture checkout names independence of git config

e2ff88c

refactor(git): remove GitShortID newtype

dd6a53d

Cargo now computes the abbreviation itself and already holds a `String`. The newtype is no longer needed.

rustbot assigned epage Jul 31, 2026

rustbot added A-git Area: anything dealing with git S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jul 31, 2026

weihanglo commented Jul 31, 2026

View reviewed changes

epage approved these changes Jul 31, 2026

View reviewed changes

epage enabled auto-merge July 31, 2026 18:12

epage added this pull request to the merge queue Jul 31, 2026

Merged via the queue into rust-lang:master with commit c6dd6ae Jul 31, 2026
29 checks passed

rustbot removed the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jul 31, 2026

weihanglo deleted the git-rev branch July 31, 2026 19:29

weihanglo mentioned this pull request Aug 4, 2026

Update cargo submodule rust-lang/rust#160527

Merged

rustbot added this to the 1.99.0 milestone Aug 6, 2026

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fix(git): make checkout names independent of git config - #17289

fix(git): make checkout names independent of git config#17289
epage merged 3 commits into
rust-lang:masterfrom
weihanglo:git-rev

weihanglo commented Jul 31, 2026

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weihanglo Jul 31, 2026 •

edited by rustbot

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weihanglo commented Jul 31, 2026

What does this PR try to resolve?

How to test and review this PR?

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weihanglo Jul 31, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

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weihanglo Jul 31, 2026 •

edited by rustbot

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