diff -up firefox-88.0/testing/xpcshell/runxpcshelltests.py.old firefox-88.0/testing/xpcshell/runxpcshelltests.py

--- firefox-88.0/testing/xpcshell/runxpcshelltests.py.old	2021-04-30 10:45:14.466616224 +0200

+++ firefox-88.0/testing/xpcshell/runxpcshelltests.py	2021-04-30 10:45:21.339525085 +0200

@@ -1382,8 +1382,8 @@ class XPCShellTests(object):

                         self.log.info("Process %s" % label)

                     self.log.info(msg)

-            dumpOutput(proc.stdout, "stdout")

-            dumpOutput(proc.stderr, "stderr")

+            #dumpOutput(proc.stdout, "stdout")

+            #dumpOutput(proc.stderr, "stderr")

         self.nodeProc = {}

     def startHttp3Server(self):