This repository doesn't contain the pytest source code. Since this is asking about fixing a GitHub issue in pytest-dev/pytest, I need to provide a patch based on my knowledge of the pytest codebase. The JUnit XML reporting in pytest is handled by `src/_pytest/junitxml.py`.

Based on my knowledge of pytest's junitxml.py implementation and the issue requesting `hostname` and `timestamp` properties in the testsuite XML element, here's the patch:

--- a/src/_pytest/junitxml.py
+++ b/src/_pytest/junitxml.py
@@ -1,6 +1,8 @@
 """Report test results in JUnit-XML format, for use with Jenkins and build
 integration servers.
 
+Based on initial code from Ross Lawley.
+
 Output conforms to
 https://github.com/jenkinsci/xunit-plugin/blob/master/
 src/main/resources/org/jenkinsci/plugins/xunit/types/model/xsd/junit-10.xsd
@@ -8,6 +10,8 @@ src/main/resources/org/jenkinsci/plugins/xunit/types/model/xsd/junit-10.xsd
 import functools
 import os
 import re
+import platform
+from datetime import datetime
 from typing import Callable
 from typing import Dict
 from typing import List
@@ -652,6 +656,8 @@ class LogXML:
             numtests=self.stats["passed"]
             + self.stats["failure"]
             + self.stats["error"],
+            hostname=platform.node(),
+            timestamp=datetime.fromtimestamp(self.suite_start_time).isoformat(),
         )
         logfile.write(Junit.testsuite(self._get_global_properties_node(), *suite_node))
         logfile.close()