How to run a command in every git worktree

You have a handful of worktrees and one command to run in all of them: the test suite, a git status, a dependency install. Git ships git submodule foreach but never shipped git worktree foreach, so the answer you will find is a hand-written loop. Here is the version that actually behaves:

status=0
while read -r _ path; do
    (cd "$path" && ./scripts/test) || { echo "FAILED: $path" >&2; status=1; }
done < <(git worktree list --porcelain | grep "^worktree ")
exit $status

Every part of that is load-bearing, and the rest of this post is the evidence: I built a scratch project with three worktrees, broke the test in one of them, and ran the four loop variants the internet suggests. Three of the four got it wrong, each differently.

Variant 1: the pipe that reports and then lies

The most common answer pipes into while read and appends an || echo:

$ git worktree list --porcelain | grep "^worktree " | while read -r _ path; do
    (cd "$path" && ./scripts/test) || echo "failed: $path"
  done
failed: .../wts/TICKET-1102
$ echo $?
0

It tells you TICKET-1102 failed and then exits 0. The pipe runs the loop in a subshell, so nothing you record inside it survives, and the pipeline’s status is the loop’s, which succeeded. In CI this is a green build with a broken worktree. The fix is the process substitution in the version up top: the loop runs in your shell, so status=1 sticks.

Variant 2: no error handling, with and without set -e

Drop the || entirely, which is how most one-off loops get typed:

• Without set -e: the failure vanishes. Loop exits 0, nothing printed, nothing recorded.
• With set -e (a script): the first failing worktree aborts the whole sweep. In my run, TICKET-1102 failed and TICKET-1103 was never visited. You do not learn whether the rest passes, which was the whole question.

Same loop, two shells, two different wrong answers.

Variant 3: awk, until a path has a space

Plenty of answers skip --porcelain and parse the human output:

$ for path in $(git worktree list | awk '{print $1}'); do
    (cd "$path" && ./scripts/test) || echo "failed: $path"
  done
cd: .../wts/hotfix: No such file or directory
failed: .../wts/hotfix

The worktree is called hotfix urgente. Word splitting cut it at the space and the loop visited a directory that does not exist. One honest footnote: the --porcelain + read -r _ path form survives spaces, because read puts the rest of the line in its last variable; it is the unquoted $( ) and awk forms that break. Paths with newlines need --porcelain -z, at which point the loop stops fitting in a comment box.

The entry nobody filters

git worktree list includes the main checkout as its first entry. Every loop above ran the command there too. Sometimes that is what you want; often it silently is not (the command mutates state you meant to keep clean in main). Either way, the loop does not ask.

What the loop looks like as a command

pwt ships the loop as pwt for-each, with the failure handling the DIY versions kept getting wrong. Same scratch project, same broken worktree:

$ pwt for-each ./scripts/test
=== @ (main) ===
=== TICKET-1101 ===
=== TICKET-1102 ===
=== TICKET-1103 ===
✗ Command failed in 1 of 4 worktrees: TICKET-1102
$ echo $?
1

Every worktree gets a labeled header, the main checkout runs first and is explicitly marked @, the sweep continues past failures, and the exit is non-zero with the failing worktrees named. Each worktree also gets its PWT_* environment, so the command can use the things pwt already knows:

pwt for-each 'curl -s localhost:$PWT_PORT/health'   # each worktree's own port
pwt for-each migrate                                # a Pwtfile function, per worktree

The second form is the quiet superpower: if migrate is a function in your Pwtfile, for-each runs it with each worktree’s port, branch and path filled in, which is how “run the migration everywhere” stops needing any loop at all.

Full disclosure, because this blog measures its own tool by the same rules: until this week pwt for-each had variant 2’s bug. It printed a checkmark and exited 0 no matter what failed. Writing this post is what exposed it; the fix (aggregate per-worktree exit codes, name the failures, exit non-zero) shipped with tests that were first run against the old binary to prove they caught it.

brew install jonasporto/pwt/pwt, and pwt for-each is there after a pwt init (reference). The loop at the top of this post remains correct if you would rather own it yourself.

You do not have to memorize any of this. pwt skill prints the agent-facing guide to pwt; tell your agent the outcome you want and point it there, and it works out the mechanism and verifies it in a throwaway worktree.

for-each is part of that guide: ask the agent to do something “in all worktrees” and it reaches for pwt for-each by default, including the aggregated failure report, instead of typing one of the loops above. Reference: pwt for-each.