From c1a85bb6debb6f20a19d8699f2a009fadd4ed9d2 Mon Sep 17 00:00:00 2001
From: Damien George <damien@micropython.org>
Date: Wed, 6 Nov 2024 12:43:04 +1100
Subject: [PATCH] tools/mpremote: Make sure stdout and stderr output appear in
 order.

mpremote error messages now go to stderr, so make sure stdout is flushed
before printing them.

Also update the test runner to capture error messages.

Signed-off-by: Damien George <damien@micropython.org>
---
 tools/mpremote/mpremote/main.py            | 3 +++
 tools/mpremote/tests/run-mpremote-tests.sh | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/mpremote/mpremote/main.py b/tools/mpremote/mpremote/main.py
index 8c0a6cd22..e6e397020 100644
--- a/tools/mpremote/mpremote/main.py
+++ b/tools/mpremote/mpremote/main.py
@@ -547,7 +547,10 @@ def main():
 
         return 0
     except CommandError as e:
+        # Make sure existing stdout appears before the error message on stderr.
+        sys.stdout.flush()
         print(f"{_PROG}: {e}", file=sys.stderr)
+        sys.stderr.flush()
         return 1
     finally:
         do_disconnect(state)
diff --git a/tools/mpremote/tests/run-mpremote-tests.sh b/tools/mpremote/tests/run-mpremote-tests.sh
index 11d82c9bb..b25b5fd7d 100755
--- a/tools/mpremote/tests/run-mpremote-tests.sh
+++ b/tools/mpremote/tests/run-mpremote-tests.sh
@@ -16,7 +16,7 @@ for t in $TESTS; do
     TMP=$(mktemp -d)
     echo -n "${t}: "
     # Strip CR and replace the random temp dir with a token.
-    if env MPREMOTE=${MPREMOTE} TMP="${TMP}" "${t}" | tr -d '\r' | sed "s,${TMP},"'${TMP},g' > "${t}.out"; then
+    if env MPREMOTE=${MPREMOTE} TMP="${TMP}" "${t}" 2>&1 | tr -d '\r' | sed "s,${TMP},"'${TMP},g' > "${t}.out"; then
         if diff "${t}.out" "${t}.exp" > /dev/null; then
             echo "OK"
         else