src/Pure/Admin/build_release.scala

     /* make distribution */
 
     val jobs_option = " -j" + parallel_jobs.toString
 
     if (release_info.dist_archive.is_file)
-      progress.echo("Release archive " + release_info.dist_archive + " already exists")
+      progress.echo("### Release archive already exists: " + release_info.dist_archive)
     else {
       progress.echo("Producing release archive " + release_info.dist_archive + " ...")
       progress.bash(
         "isabelle makedist -d " + File.bash_path(base_dir) + jobs_option +
           (if (official_release) " -O" else "") +

           Path.explode(
             if (platform_family == "macos" && remote_mac.isEmpty)
               release_info.name + "_dmg.tar.gz"
             else platform_bundle)
       if (bundle_archive.is_file)
-        progress.echo("Application bundle " + bundle_archive + " already exists")
+        progress.echo("### Application bundle already exists: " + bundle_archive)
       else {
         progress.echo("\n*** " + platform_family + ": " + bundle_archive + " ***")
         progress.bash(
           "isabelle makedist_bundle " + File.bash_path(release_info.dist_archive) +
             " " + File.bash_string(platform_family) +

 
     /* HTML library */
 
     if (build_library) {
       if (release_info.dist_library_archive.is_file)
-        progress.echo("Library archive " + release_info.dist_library_archive + " already exists")
+        progress.echo("### Library archive already exists: " + release_info.dist_library_archive)
       else {
         progress.bash("\"$ISABELLE_HOME/Admin/Release/build_library\"" + jobs_option + " " +
           File.bash_path(release_info.dist_dir +
             Path.explode(release_info.name + "_" +
               Isabelle_System.getenv_strict("ISABELLE_PLATFORM_FAMILY") + ".tar.gz"))).check