fix(action): better logging

Be more clear about why it failed

comment_on_pr.sh

@@ -2,6 +2,11 @@
 
 set -eu
 
+util_path="${GITHUB_ACTION_PATH-.}/utils.sh"
+
+# shellcheck source=utils.sh
+. "${util_path}"
+
 # USAGE: json_to_md_rows <FIELD> [JSON_FILE]
 #
 # JSON_FILE can be piped from stdin
@@ -96,11 +101,11 @@ if [ "${CI-false}" != 'true' ]; then
 	exit 0
 fi
 
-echo 'Determine head_ref'
+log 'Determine head_ref'
 # For push & tag events it'll bet GITHUB_REF_NAME, for pull_request events it'll be GITHUB_HEAD_REF
 head_ref=${GITHUB_REF_NAME-$GITHUB_HEAD_REF}
 
-echo "Get PR number for $head_ref"
+log "Get PR number for $head_ref"
 prs=$(curl -X 'GET' \
 	"$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/pulls?state=open&sort=recentupdate" \
 	-H "Authorization: token $GITHUB_TOKEN" \
@@ -111,22 +116,25 @@ pr_number=$(echo "$prs" |
 
 # Protect against running before a PR is made or if it is triggered on the main branch
 if [ -z "$pr_number" ]; then
-	echo "No PR created for this commit"
+	log "No PR created for this commit"
 	exit 0
 fi
 
-echo "Retrieved index: $pr_number" >&2
-echo "Expected PR URL: $GITHUB_SERVER_URL/$GITHUB_REPOSITORY/pulls/$pr_number" >&2
+log "Retrieved index: $pr_number"
+log "Expected PR URL: $GITHUB_SERVER_URL/$GITHUB_REPOSITORY/pulls/$pr_number"
 
-echo 'Generating comment body' >&2
+log 'Generating comment body'
 comment=$(markdown_from_report "$@")
 
-echo 'Posting comment:' >&2
-echo "$comment" >&2
+group 'Comment Data:'
+log "$comment"
+endgroup
 
-echo 'Request data:' >&2
 data=$(echo '{}' | jq --arg comment "$comment" '.body=$comment')
-echo "$data" >&2
+group 'Request data:'
+log "$data"
+endgroup
+
 curl -o - -X 'POST' \
 	"$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/issues/$pr_number/comments" \
 	-H 'accept: application/json' \