From fba21ad5a6152d7f1bf6a74111bc47f9a86bcf20 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Wed, 6 May 2026 22:11:09 +0000
Subject: [PATCH] fix(quic-interop): use a fresh per-invocation log subdir

run.py refuses to start if --log-dir already exists (interop.py:81-82
calls sys.exit). Previous script eagerly mkdir'd $LOG_DIR, which made
the second run always fail.

New layout: $LOG_DIR is the parent (created if missing), each
invocation writes to $LOG_DIR/run-YYYYmmdd-HHMMSS/. Preserves history
of past runs instead of overwriting; latest is `ls -t $LOG_DIR | head -1`.

https://claude.ai/code/session_01HcvfQq1ttPV9PkRoJb4nyT
---
 quic/interop/run-matrix.sh | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/quic/interop/run-matrix.sh b/quic/interop/run-matrix.sh
index a790be72a..e336eee3f 100755
--- a/quic/interop/run-matrix.sh
+++ b/quic/interop/run-matrix.sh
@@ -91,8 +91,13 @@ if [ "${SKIP_BUILD:-0}" != "1" ]; then
 fi
 
 # 5. Drive the runner.
+#
+# run.py hard-exits if --log-dir already exists, so we use a fresh
+# per-invocation subdirectory under $LOG_DIR. The parent must exist; the
+# child must not. Tail of `ls -t "$LOG_DIR" | head -1` finds the latest.
 mkdir -p "$LOG_DIR"
-echo "==> running matrix (args: $* | logs: $LOG_DIR)"
+RUN_LOG_DIR="$LOG_DIR/run-$(date +%Y%m%d-%H%M%S)"
+echo "==> running matrix (args: $* | logs: $RUN_LOG_DIR)"
 cd "$RUNNER_DIR"
 exec "$RUNNER_DIR/.venv/bin/python" run.py \
-    -d -i amethyst --log-dir "$LOG_DIR" "$@"
+    -d -i amethyst --log-dir "$RUN_LOG_DIR" "$@"