From e4a99d5551ff7808c4f735958a7b63951c17e5e9 Mon Sep 17 00:00:00 2001
From: Weihang Lo <me@weihanglo.tw>
Date: Sun, 16 Aug 2026 12:57:23 -0400
Subject: [PATCH] fix(git): `git gc` with `safe.bareRepository=explicit`

Git v3 will enforce `safe.bareRepository=explicit`,
while older versions don't.
See <https://git-scm.com/docs/BreakingChanges/2.55.0#_git_3_0>

This ensures `git gc` work with `safe.bareRepository=explicit`
by setting an explicit `GIT_DIR` environment variable.
This is not a requirement of making CLI fetch the default,
but better to have before Git CLI v3 is out.
---
 src/sources/git/utils.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/sources/git/utils.rs b/src/sources/git/utils.rs
index b4f07784d23..21996626098 100644
--- a/src/sources/git/utils.rs
+++ b/src/sources/git/utils.rs
@@ -1462,7 +1462,11 @@ fn maybe_gc_repo(repo: &mut git2::Repository, gctx: &GlobalContext) -> CargoResu
     if let Ok(limit) = gctx.get_env("__CARGO_PACKFILE_LIMIT") {
         cmd.arg(format!("-c gc.autoPackLimit={}", limit));
     }
-    cmd.arg("gc").arg("--auto").current_dir(repo.path());
+    cmd.arg("gc")
+        .arg("--auto")
+        // Explicitly set `GIT_DIR` so `safe.bareRepository=explicit` doesn't reject it.
+        .env("GIT_DIR", repo.path())
+        .current_dir(repo.path());
 
     match cmd.output() {
         Ok(out) => {