smoketest: say once a minute that a command in the VM is still running

run_in_vm prints how long it has run and the log's latest line, so an
hour-long install.sh shows progress without tail -f.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

smoketest/lib/scenario.sh

@@ -48,17 +48,36 @@ skip() {
 # run_in_vm NAME SCRIPT: run SCRIPT in the VM, keeping its output in $OUTPUT,
 # its exit status in $STATUS, and both in NN-NAME.log. Doesn't fail on its own:
 # check with assert_status. The log is written as SCRIPT runs, so a long one
-# (install.sh takes an hour or more) can be followed with tail -f.
+# (install.sh takes an hour or more) can be followed with tail -f, and once a
+# minute run_in_vm says it's still running, with the log's latest line.
 run_in_vm() {
+  local ticker
   RUN_COUNT=$((RUN_COUNT + 1))
   LAST_RUN="$1"
   LAST_LOG="$SMOKETEST_RESULTS/$(printf '%02d' "$RUN_COUNT")-$1.log"
   echo "== $1 (to follow it: tail -f $LAST_LOG)"
+  : > "$LAST_LOG"
+  progress_ticker "$1" "$LAST_LOG" &
+  ticker=$!
   vm_exec "$2" > "$LAST_LOG" 2>&1 && STATUS=0 || STATUS=$?
+  kill "$ticker" 2> /dev/null
+  wait "$ticker" 2> /dev/null || true
   OUTPUT="$(cat "$LAST_LOG")"
   echo "== $1 exited $STATUS (log: $LAST_LOG)"
 }
 
+# progress_ticker NAME LOG: every SMOKETEST_TICK seconds (60), say NAME is
+# still running, for how long, and LOG's latest line. run_in_vm kills it.
+# sleep gets no stdout, so a killed ticker leaves nothing holding the driver's
+# pipe to tee open.
+progress_ticker() {
+  local start=$SECONDS tick="${SMOKETEST_TICK:-60}" last
+  while sleep "$tick" > /dev/null 2>&1 3>&-; do
+    last="$(tail -c 4096 "$2" | tr '\r' '\n' | grep -v '^[[:space:]]*$' | tail -n 1 | cut -c 1-100)"
+    echo "  still running $1 ($(( (SECONDS - start) / 60 )) min)${last:+: $last}"
+  done
+}
+
 # Called by the driver once the VM is up, before the scenario
 smoketest_prepare() {
   local urls="" url

tests/smoketest.bats

@@ -138,6 +138,14 @@ upstream_main() {
   [ -f "$SMOKETEST_RESULTS/02-second.log" ]
 }
 
+@test "run_in_vm says once a tick that it's still running, with the log's latest line" {
+  export SMOKETEST_TICK=1
+  run run_in_vm slow 'echo working; sleep 2.5'
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"  still running slow (0 min): working"* ]]
+  [[ "$output" == *"== slow exited 0 (log: "* ]]
+}
+
 @test "run_in_vm writes its log while the script runs" {
   run_in_vm slow 'echo early; cat "$SMOKETEST_RESULTS/01-slow.log" > "$HOME/seen"'
   [ "$STATUS" -eq 0 ]