--- a/python/mozbuild/mozbuild/backend/tup.py
+++ b/python/mozbuild/mozbuild/backend/tup.py
@@ -648,18 +648,27 @@ class TupBackend(CommonBackend):
 
             if any(f.endswith(('automation.py', 'source-repo.h', 'buildid.h'))
                    for f in obj.outputs):
                 extra_outputs = [self._early_generated_files]
             else:
                 extra_outputs = [self._installed_files] if obj.required_for_compile else []
                 full_inputs += [self._early_generated_files]
 
+            if len(outputs) > 3:
+                display_outputs = ', '.join(outputs[0:3]) + ', ...'
+            else:
+                display_outputs = ', '.join(outputs)
+            display = 'python {script}:{method} -> [{display_outputs}]'.format(
+                script=obj.script,
+                method=obj.method,
+                display_outputs=display_outputs
+            )
             backend_file.rule(
-                display='python {script}:{method} -> [%o]'.format(script=obj.script, method=obj.method),
+                display=display,
                 cmd=cmd,
                 inputs=full_inputs,
                 outputs=outputs,
                 extra_outputs=extra_outputs,
                 check_unchanged=True,
             )
 
     def _process_defines(self, backend_file, obj, host=False):