From b02813821b08d0d5d000dd9fda3e834f8cf9b380 Mon Sep 17 00:00:00 2001
From: Jeremy Daer <jeremy@37signals.com>
Date: Mon, 3 Aug 2026 19:58:16 -0700
Subject: [PATCH] Stop a losing rm -rf race from failing a passing test
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update_nix_flake.bats builds a throwaway git repo per test, and under
`bats -j` teardown's `rm -rf` intermittently fails with ENOTEMPTY on
.git/objects. bats counts a failing teardown as a failing test, so a
green assertion gets reported red — twice in six local bin/ci runs,
landing on a different test name each time.

ENOTEMPTY says the directory was not empty when rm reached it. It does
not say what refilled it, and I have not established that, so the fix
goes at the teardown rather than at a presumed cause: retry briefly,
then give up quietly. Cleanup should not decide whether a test passed,
and a leftover directory under TMPDIR is worth less than a signal people
trust.
---
 e2e/update_nix_flake.bats | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/e2e/update_nix_flake.bats b/e2e/update_nix_flake.bats
index a9793697..5140d782 100644
--- a/e2e/update_nix_flake.bats
+++ b/e2e/update_nix_flake.bats
@@ -38,7 +38,23 @@ NIXPKG
 }
 
 teardown() {
-  rm -rf "$WORK"
+  # Cleanup must not decide whether the test passed. Under `bats -j` these tests
+  # each build a throwaway git repo in $TMPDIR, and on macOS `rm -rf`
+  # intermittently fails with ENOTEMPTY on .git/objects. bats treats a failing
+  # teardown as a failing test, so a green assertion was reported red — twice in
+  # six local runs, landing on a different test name each time.
+  #
+  # ENOTEMPTY says the directory was not empty when rm reached it; it does not
+  # say what refilled it, and that has not been established. Hence a fix at the
+  # teardown rather than at a presumed cause: retry briefly, then give up
+  # quietly. A leftover directory under $TMPDIR is worth less than a trustworthy
+  # signal, and the assertions have already run either way.
+  for _ in 1 2 3; do
+    rm -rf "$WORK" 2>/dev/null && return 0
+    sleep 0.1
+  done
+  rm -rf "$WORK" 2>/dev/null || true
+  return 0
 }
 
 # Emits a canned nix log plus the sentinel the script reads for exit status.