sync: implement reprojectcmd for the local half

2026-09-15T19:53:01+00:00

Add `repo.reprojectcmd`, the checkout counterpart to `repo.fetchcmd`. When set, `repo sync` runs this command instead of Git to materialize a project's index and worktree at the target tree, while `repo` handles ref updates directly via `git update-ref`. This replaces Git's tree materialization steps: detaching HEAD, fast-forwarding, and hard-resetting. Rebasing is not delegated, and the command is skipped if HEAD is already at the target, if HEAD is ahead of the target during fast-forward, or for MetaProjects. The command runs in a subshell with project environment variables (such as `REPO_TREV`). Before running, `repo` ensures no operation is in progress and no staged changes exist. Worktree collision detection is delegated to the command (preserving benign unstaged/untracked edits). Afterward, `repo` verifies that HEAD was untouched and that the index matches the target tree. Like `repo.fetchcmd`, this requires `repo.uselocalgitdirs`. Nested projects and submodules are unsupported; `repo sync` fails if the manifest contains any while `repo.reprojectcmd` is enabled. Verified end-to-end with repo init using local-gitdirs, repo.fetchcmd, and repo.reprojectcmd ('git -C $REPO_PATH read-tree -m -u $REPO_TREV'): * Verified detached HEAD checkout and correct reflog generation across projects. * Verified benign unstaged edits and untracked files survive checkout. * Verified conflicting untracked files fail with exit 128 without clobbering worktree. * Verified staged changes fail upfront before reprojectcmd is executed. Bug: 513329573 Change-Id: I964d24d22dccffc05a9b991ad69f3a7e93268c01 Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/626281 Tested-by: Gavin Mak Reviewed-by: Brian Gan Commit-Queue: Gavin Mak

sync: Implement fetchcmd for standard Git layouts

2026-06-30T20:20:15+00:00

Introduce support for `repo.fetchcmd` configuration, allowing users to specify a custom command to fetch project data instead of `_RemoteFetch`. When `repo.fetchcmd` is specified, `repo` will execute it instead of `_RemoteFetch` during the network half of sync. Note that `repo.fetchcmd` requires `repo.uselocalgitdirs` to be enabled. The command is executed in a subshell with project-context environment variables, including the new `REPO_TREV` (target revision resolved to a commit hash) and `REPO_PROJECT_FETCH_URL`. After execution, `repo` verifies that the target commit is available and that the tracking ref and FETCH_HEAD are correctly updated. Tested with: ``` > ~/git-repo/repo init -u https://android-review.googlesource.com/platform/manifest \ --repo-url file:///usr/local/google/home/gavinmak/git-repo \ --groups developers \ --no-repo-verify \ --use-local-gitdirs ... > git config --file .repo/manifests.git/config repo.fetchcmd 'mkdir -p $REPO_PATH && cd $REPO_PATH && if [ ! -d .git ]; then git init && git remote add aosp $REPO_PROJECT_FETCH_URL; fi && git fetch aosp $REPO_TREV && git reset --hard $REPO_TREV && mkdir -p .git/refs/remotes/aosp && echo $REPO_TREV > .git/refs/remotes/aosp/main && echo $REPO_TREV > .git/FETCH_HEAD' > ~/git-repo/repo sync -j32 warning: repo is not tracking a remote branch, so it will not receive updates; run `repo init --repo-rev=stable` to fix. You are currently enrolled in Git submodules experiment (go/android-submodules-quickstart). Use --no-use-superproject to override. Syncing: 100% (4/4), done in 1m15.686s Finalizing sync state... repo sync has finished successfully. ``` Bug: 513329573 Change-Id: I754d3f3c78e86fdeee1a72115297a75b571bc497 Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/583883 Reviewed-by: Becky Siegel Tested-by: Gavin Mak Commit-Queue: Gavin Mak

tools/git-repo.git/docs/fetch-cmd.md, branch v2.68.1

sync: implement reprojectcmd for the local half

sync: Implement fetchcmd for standard Git layouts