Flake fix: build test timeout

The priv test added to the build test in June runs an 'apk'
command which, unavoidably, has to fetch stuff from the net.
This is slow and unreliable, and periodically leads to
timeout failures. Worse, when this happens, some sort of
invisible buildah-only container gets left behind that leads
to failures in subsequent tests when trying to reset to
known state.

Imperfect workaround: try a 240-second timeout (up from 60)
when running apk. As backup, add a custom teardown() which
attempts to force-remove all containers and any new images.

Signed-off-by: Ed Santiago <santiago@redhat.com>

test/system/070-build.bats

@@ -22,12 +22,24 @@ RUN apk add nginx
 RUN echo $rand_content > /$rand_filename
 EOF
 
-    run_podman build -t build_test --format=docker $tmpdir
+    # The 'apk' command can take a long time to fetch files; bump timeout
+    PODMAN_TIMEOUT=240 run_podman build -t build_test --format=docker $tmpdir
     is "$output" ".*STEP 4: COMMIT" "COMMIT seen in log"
 
     run_podman run --rm build_test cat /$rand_filename
     is "$output"   "$rand_content"   "reading generated file in image"
 
-    run_podman rmi build_test
+    run_podman rmi -f build_test
 }
+
+function teardown() {
+    # A timeout or other error in 'build' can leave behind stale images
+    # that podman can't even see and which will cascade into subsequent
+    # test failures. Try a last-ditch force-rm in cleanup, ignoring errors.
+    run_podman '?' rm -a -f
+    run_podman '?' rmi -f build_test
+
+    basic_teardown
+}
+
 # vim: filetype=sh