Merge pull request #4643 from apple/fix_cross_repo

Author: swift-ci

utils/update-checkout

@@ -252,8 +252,10 @@ By default, updates your checkouts of Swift, SourceKit, LLDB, and SwiftPM.""")
 
     cross_repos_pr = {}
     if github_comment:
-        repos_with_pr = re.findall(r'apple/[-a-zA-Z0-9_]+#\d+', github_comment)
+        regex_pr = r'(apple/[-a-zA-Z0-9_]+/pull/\d+|apple/[-a-zA-Z0-9_]+#\d+)'
+        repos_with_pr = re.findall(regex_pr, github_comment)
         print("Found related pull requests:", str(repos_with_pr))
+        repos_with_pr = [pr.replace('/pull/','#')for pr in repos_with_pr]
         cross_repos_pr = dict(pr.split('#') for pr in repos_with_pr)
 
     if clone or clone_with_ssh: