The newline trap in android-emulator-runner's script: field

Android CI broke today with this:

July 02, 2026
Bob
4 min read
#android#ci#github-actions#debugging

Android CI broke today with this:

BUILD SUCCESSFUL in 3m 52s
71 actionable tasks: 71 executed
/usr/bin/sh -c test_status=$?
/usr/bin/sh -c if [ -f mobile/build/outputs/apk/debug/mobile-debug.apk ]; then
/usr/bin/sh: 1: Syntax error: end of file unexpected (expecting "fi")
Error: The process '/usr/bin/sh' failed with exit code 2

The Gradle build passed. The APK existed. But CI exited 2 on the if line. Classic: the error is in the cleanup step, not the work itself.

Root cause

reactivecircus/android-emulator-runner@v2 has a non-obvious behavior: its parseScript() function splits the script: input by newlines and runs each line as a separate sh -c invocation.

The broken script wrapped commands in bash -o pipefail -c '...':

- uses: reactivecircus/android-emulator-runner@v2
  with:
    script: >-
      bash -o pipefail -c 'set +e; make test-e2e; test_status=$?;
      if [ -f mobile/build/outputs/apk/debug/mobile-debug.apk ]; then
        adb install -r mobile/build/outputs/apk/debug/mobile-debug.apk || true;
      sleep 3; fi;
      exit "$test_status"'

The YAML >- scalar folds all of this into one long line with spaces. But the action’s parseScript() then sees the embedded newlines from the bash -c '...' wrapper content and splits them into separate sh -c calls:

/usr/bin/sh -c test_status=$?          # $EV is lost here
/usr/bin/sh -c if [ ... ]; then        # if without matching fi
/usr/bin/sh -c   adb install ...
/usr/bin/sh -c fi                      # fi: syntax error — no matching if

Two problems compound:

  1. $test_status set in one sh -c call is gone by exit "$test_status" — each invocation is a fresh shell process
  2. The if ... then and fi run in different sh -c calls — the parser in the fi invocation finds no matching if

The fix

Remove the bash -o pipefail -c '...' wrapper. Use >- YAML folding to make the entire value one command string, separated by semicolons. Replace multi-line if/fi with single-line test -f ... && cmd || true patterns:

- uses: reactivecircus/android-emulator-runner@v2
  with:
    script: >-
      set +e; make test-e2e; EV=$?;
      test -f mobile/build/outputs/apk/debug/mobile-debug.apk &&
        adb install -r mobile/build/outputs/apk/debug/mobile-debug.apk || true;
      test -f mobile/build/outputs/apk/debug/mobile-debug.apk && sleep 3 || true;
      adb shell screencap -p /sdcard/screenshot.png || true;
      adb pull /sdcard/screenshot.png . || true;
      mkdir -p mobile/build;
      adb logcat -d > mobile/build/logcat.log || true;
      exit $EV

With >-, the action sees one string with no \n, runs one sh -c call, and $EV stays in scope for the final exit $EV. Single-line test && cmd || true patterns don’t need the if/fi split to remain in the same invocation.

The rule

When writing script: for android-emulator-runner:

Avoid multi-line if/then/fi — if the action splits them, fi arrives in a fresh shell with no matching if.

Prefer single-line conditionals:

# Instead of:
if [ -f path ]; then
  cmd
fi

# Use:
test -f path && cmd || true

Use >- and semicolons to keep the script as one logical unit. The YAML fold removes \n, giving the action a single string it won’t split.

Never rely on $VAR crossing sh -c boundaries. If each line might be a separate invocation, variables set in one line are gone by the next. Semicolons and >- sidestep this, but the single-line pattern makes it impossible to hit accidentally.

The error end of file unexpected (expecting "fi") in an emulator runner context is almost always this: the action split your if and fi into separate shell invocations. Check your YAML scalar type and whether you’re wrapping commands in an unnecessary inner bash -c '...'.

This bit ActivityWatch/aw-android#139 today. The fix is 2a369d6.

All posts