diff --git a/infinitepush/backupcommands.py b/infinitepush/backupcommands.py
--- a/infinitepush/backupcommands.py
+++ b/infinitepush/backupcommands.py
@@ -465,14 +465,15 @@
         batch.lookup(hexnode)
     batch.submit()
     lookupresults = batch.results()
+    i = 0
     try:
-        for r in lookupresults:
+        for i, r in enumerate(lookupresults):
             # iterate over results to make it throw if revision
             # was not found
             pass
         return True
-    except error.RepoError as e:
-        ui.warn(_('%s\n') % e)
+    except error.RepoError:
+        ui.warn(_('unknown revision %r\n') % remotehexnodes[i])
         return False
 
 _backuplatestinfofile = 'infinitepushlatestbackupinfo'
diff --git a/tests/test-infinitepush-pullbackup.t b/tests/test-infinitepush-pullbackup.t
--- a/tests/test-infinitepush-pullbackup.t
+++ b/tests/test-infinitepush-pullbackup.t
@@ -221,7 +221,13 @@
   [255]
   $ hg debugcheckbackup --user anotheruser --reporoot $TESTTMP/backupsource
   checking \$TESTTMP/backupsource on .* (re)
+  unknown revision 'e0230a60975b38a9014f098fb973199efd25c46f'
+  [255]
   $ hg debugcheckbackup --all | sort
+  unknown revision 'c1bfda8efb6e73473d6874e35125861a34a5594d'
+  unknown revision 'a2a9ae518b62f1d9d1e884d2c16f87bb2e368c5c'
+  unknown revision 'a2a9ae518b62f1d9d1e884d2c16f87bb2e368c5c'
+  unknown revision '33c1c9df81e943319194decdb886cced08e67a29'
   checking \$TESTTMP on .* (re)
   checking \$TESTTMP/backupsource on .* (re)
   checking \$TESTTMP/backupsource2 on .* (re)
@@ -245,6 +251,7 @@
   finished in \d+\.(\d+)? seconds (re)
   $ cd ../backupsource
   $ hg debugcheckbackup --user anotheruser --all | sort
+  unknown revision 'c03baa769a209c549603380d7bf496aaf42687bb'
   unknown revision 'e0230a60975b38a9014f098fb973199efd25c46f'
   checking \$TESTTMP/backupsource on .* (re)
   checking \$TESTTMP/backupsource2 on .* (re)