Bug 1416314 - Guard against psutil exceptions when generating system-info.log; r=jmaher

It seems psutil can throw a wide range of exceptions when accessing system
information on aws...intermittently, of course. Let's expect and discard
such exceptions so that test jobs are not dependent on creating system-info.log.

testing/mozharness/scripts/desktop_unittest.py

@@ -676,32 +676,34 @@ class DesktopUnittest(TestingMixin, MercurialScript, BlobUploadMixin, MozbaseMix
         """
         try:
             import psutil
+            dir = self.query_abs_dirs()['abs_blob_upload_dir']
+            self.mkdir_p(dir)
+            path = os.path.join(dir, "system-info.log")
+            with open(path, "w") as f:
+                self._report_line(f, "System info collected at ", datetime.now())
+                self._report_line(f, "\nBoot time ",
+                                  datetime.fromtimestamp(psutil.boot_time()))
+                self._report_line(f, "\nVirtual memory: ", psutil.virtual_memory())
+                self._report_line(f, "\nDisk partitions: ", psutil.disk_partitions())
+                self._report_line(f, "\nDisk usage (/): ", psutil.disk_usage(os.path.sep))
+                self._report_line(f, "\nUsers: ", psutil.users())
+                self._report_line(f, "\nNetwork connections:", "")
+                try:
+                    for nc in psutil.net_connections():
+                        self._report_line(f, "  ", nc)
+                except:
+                    f.write("Exception getting network info: %s" % sys.exc_info()[0])
+                self._report_line(f, "\nProcesses:", "")
+                try:
+                    for p in psutil.process_iter():
+                        ctime = str(datetime.fromtimestamp(p.create_time()))
+                        self._report_line(f, "  PID", "%d %s %s created at %s" %
+                                          (p.pid, p.name(), str(p.cmdline()), ctime))
+                except:
+                    f.write("Exception getting process info: %s" % sys.exc_info()[0])
         except:
-            return
-        dir = self.query_abs_dirs()['abs_blob_upload_dir']
-        self.mkdir_p(dir)
-        path = os.path.join(dir, "system-info.log")
-        with open(path, "w") as f:
-            self._report_line(f, "System info collected at ", datetime.now())
-            self._report_line(f, "\nBoot time ", datetime.fromtimestamp(psutil.boot_time()))
-            self._report_line(f, "\nVirtual memory: ", psutil.virtual_memory())
-            self._report_line(f, "\nDisk partitions: ", psutil.disk_partitions())
-            self._report_line(f, "\nDisk usage (/): ", psutil.disk_usage(os.path.sep))
-            self._report_line(f, "\nUsers: ", psutil.users())
-            self._report_line(f, "\nNetwork connections:", "")
-            try:
-                for nc in psutil.net_connections():
-                    self._report_line(f, "  ", nc)
-            except:
-                f.write("Exception getting network info: %s" % sys.exc_info()[0])
-            self._report_line(f, "\nProcesses:", "")
-            try:
-                for p in psutil.process_iter():
-                    ctime = str(datetime.fromtimestamp(p.create_time()))
-                    self._report_line(f, "  PID", "%d %s %s created at %s" %
-                                      (p.pid, p.name(), str(p.cmdline()), ctime))
-            except:
-                f.write("Exception getting process info: %s" % sys.exc_info()[0])
+            # psutil throws a variety of intermittent exceptions
+            self.info("Unable to complete system-info.log: %s" % sys.exc_info()[0])
 
     # pull defined in VCSScript.
     # preflight_run_tests defined in TestingMixin.