diff --git a/build_tools/gnu_parallel b/build_tools/gnu_parallel
index 06a560fcf..6b7849b0e 100755
--- a/build_tools/gnu_parallel
+++ b/build_tools/gnu_parallel
@@ -1842,7 +1842,6 @@ sub start_another_job {
 }
 
 $opt::min_progress_interval = 0;
-$opt::progress_sep = "\r";
 
 sub init_progress {
     # Uses:
@@ -1852,7 +1851,6 @@ sub init_progress {
     $|=1;
     if (not $Global::is_terminal) {
       $opt::min_progress_interval = 30;
-      $opt::progress_sep = "\n";
     }
     if($opt::bar) {
 	return("","");
@@ -1878,7 +1876,9 @@ sub drain_job_queue {
     }
     my $last_header="";
     my $sleep = 0.2;
+    my $last_left = 1000000000;
     my $last_progress_time = 0;
+    my $ps_reported = 0;
     do {
         while($Global::total_running > 0) {
             debug($Global::total_running, "==", scalar
@@ -1889,15 +1889,38 @@ sub drain_job_queue {
 		    close $job->fh(0,"w");
 		}
 	    }
-            if($opt::progress and (time() - $last_progress_time) >= $opt::min_progress_interval) {
-                $last_progress_time = time();
+            # When not connected to terminal, assume CI (e.g. CircleCI). In
+            # that case we want occasional progress output to prevent abort
+            # due to timeout with no output, but we also need to stop sending
+            # progress output if there has been no actual progress, so that
+            # the job can time out appropriately (CirecleCI: 10m) in case of
+            # a hung test. But without special output, it is extremely
+            # annoying to diagnose which test is hung, so we add that using
+            # `ps` below.
+            if($opt::progress and
+               ($Global::is_terminal or (time() - $last_progress_time) >= 30)) {
                 my %progress = progress();
                 if($last_header ne $progress{'header'}) {
                     print $Global::original_stderr "\n", $progress{'header'}, "\n";
                     $last_header = $progress{'header'};
                 }
-                print $Global::original_stderr $opt::progress_sep,$progress{'status'};
-		flush $Global::original_stderr;
+                if ($Global::is_terminal) {
+                    print $Global::original_stderr "\r",$progress{'status'};
+                }
+                if ($last_left > $Global::left) {
+                    if (not $Global::is_terminal) {
+                        print $Global::original_stderr $progress{'status'},"\n";
+                    }
+                    $last_progress_time = time();
+                    $ps_reported = 0;
+                } elsif (not $ps_reported and (time() - $last_progress_time) >= 60) {
+                    # No progress in at least 60 seconds: run ps
+                    print $Global::original_stderr "\n";
+                    system("ps", "-wf");
+                    $ps_reported = 1;
+                }
+                $last_left = $Global::left;
+                flush $Global::original_stderr;
             }
 	    if($Global::total_running < $Global::max_jobs_running
 	       and not $Global::JobQueue->empty()) {
@@ -1964,10 +1987,11 @@ sub progress {
     my $eta = "";
     my ($status,$header)=("","");
     if($opt::eta) {
-	my($total, $completed, $left, $pctcomplete, $avgtime, $this_eta) =
-	    compute_eta();
-	$eta = sprintf("ETA: %ds Left: %d AVG: %.2fs  ",
-		       $this_eta, $left, $avgtime);
+      my($total, $completed, $left, $pctcomplete, $avgtime, $this_eta) =
+        compute_eta();
+      $eta = sprintf("ETA: %ds Left: %d AVG: %.2fs  ",
+        $this_eta, $left, $avgtime);
+      $Global::left = $left;
     }
     my $termcols = terminal_columns();
     my @workers = sort keys %Global::host;