fix CI on PRs from forks (#1042)

Signed-off-by: Itai Segall <itai.segall@digitalasset.com>

Author: isegall-da

.github/actions/scripts/common_setup.sh

@@ -17,7 +17,8 @@ git checkout main
 echo "GITHUB_HEAD_REF: ${GITHUB_HEAD_REF:-}"
 if [ -n "${GITHUB_HEAD_REF:-}" ] && [ "$GITHUB_HEAD_REF" != "main" ]; then
   echo "Checking out $GITHUB_HEAD_REF"
-  git checkout "$GITHUB_HEAD_REF"
+  # On PRs from forks, GITHUB_HEAD_REF is the name of the branch in the forked repo, so we cannot actually checkout that branch directly.
+  git checkout "$GITHUB_HEAD_REF" || true
 fi
 git fetch origin 'refs/heads/release-line*:refs/heads/origin/release-line*' --force
 

scripts/todo/src/checkTodos.sc

@@ -77,7 +77,8 @@ val fixedIssuesCurrentPR: Set[Int] = {
   prNumO.fold(Set.empty[Int])({ prNum =>
     val prInfo = Seq("hub", "pr", "show", "-f", "%b", prNum).!!
     val branch = Seq("hub", "pr", "show", "-f", "%H", prNum).!!.trim
-    val commits = Seq("git", "log", s"main..$branch").!!
+    // When running from forks, we don't currently check the commit messages on the branch
+    val commits = Try(Seq("git", "log", s"main..$branch").!!).getOrElse("")
     val issueCloseKeywords =
       Seq("close", "closes", "closed", "fix", "fixes", "fixed", "resolve", "resolves", "resolved")
         .map(w => s"($w)")