git checkout: Usage, Options & Common CI Errors

By Daniel Zoghalchali·Latchkey

git checkout is the classic command to switch branches and restore files.

checkout still works everywhere, but switch and restore split its two jobs more clearly. Know its detached-HEAD behavior in CI.

What it does

git checkout updates HEAD and the working tree to match a branch, tag, or commit, and can also restore individual files from a commit into the working tree.

Common usage

Terminal

git checkout main
git checkout -b feature       # create and switch
git checkout <sha>            # detached HEAD at a commit
git checkout -- file.txt      # discard working-tree changes
git checkout origin/main -- path/to/file

Options

Flag	What it does
-b <name>	Create a new branch and switch to it
-B <name>	Create or reset a branch and switch
--detach	Check out a commit without a branch
-- <path>	Restore file(s) instead of switching
-f / --force	Discard local changes when switching

Common errors in CI

error: Your local changes to the following files would be overwritten by checkout - commit or stash first. CI often lands in "detached HEAD" because it checks out a SHA; that is expected. "pathspec did not match" usually means a missing ref because of a shallow clone.

Using this in CI

CI checkouts are shallow and detached by default, which changes the answer this command gives you. Commands that read history, branch names, or tags need the checkout configured for it.

.github/workflows/ci.yml

- uses: actions/checkout@v4
  with:
    fetch-depth: 0   # history, tags, and git describe all need this

- run: |
    git rev-parse --is-shallow-repository   # expect false
    git rev-parse --abbrev-ref HEAD          # prints HEAD when detached

Frequently asked questions

git checkout: Usage, Options & Common CI Errors?