diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4b9183f9ff..ff24e39003 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -82,7 +82,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: ['ubuntu-latest']
+        os: ['ubuntu-22.04']
         python-version: ['3.7', '3.8', '3.9']
         include:
           - os: 'macos-latest'
diff --git a/metomi/rose/scripts/rose-mpi-launch b/metomi/rose/scripts/rose-mpi-launch
index b982ece580..eb507ea25a 100755
--- a/metomi/rose/scripts/rose-mpi-launch
+++ b/metomi/rose/scripts/rose-mpi-launch
@@ -128,7 +128,7 @@ while (($# > 0)); do
     --help)
         rose_help
         exit
-        :;;
+        ;;
     --command-file=*)
         ROSE_COMMAND_FILE=${1#*=}
         shift 1
@@ -153,7 +153,7 @@ while (($# > 0)); do
                 case "$OPT" in
                   '?')
                       err "ROSE_LAUNCHER_ULIMIT_OPTS=$ROSE_LAUNCHER_ULIMIT_OPTS"
-                      :;;
+                      ;;
                     *)
                       ulimit -$OPT ${OPTARG:-} || err \
                           "ROSE_LAUNCHER_ULIMIT_OPTS=$ROSE_LAUNCHER_ULIMIT_OPTS"
diff --git a/t/rose-task-run/06-app-prune-iso/flow.cylc b/t/rose-task-run/06-app-prune-iso/flow.cylc
index d720a8dd0b..f9abceb492 100644
--- a/t/rose-task-run/06-app-prune-iso/flow.cylc
+++ b/t/rose-task-run/06-app-prune-iso/flow.cylc
@@ -16,7 +16,7 @@
 {% if HOST != 'localhost' %}
                 my_task_2
 {% endif %}
-                WARM[-PT12H]:finish-all => rose_prune
+                WARM[-PT12H]:succeed-all => rose_prune
             """
 
 [runtime]