After restarting splunk master node machine (whole machine - there was no update of the splunk software itself, just underlying OS updates) the splunkd process reported on start this:
11-04-2021 11:08:22.831 +0100 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SplunkEnterpriseSecuritySuite/bin/import_icons_SplunkEnterpriseSecuritySuite.py" /opt/splunk/etc/apps/SplunkEnterpriseSecuritySuite/lib/SplunkEnterpriseSecuritySuite_app_common/solnlib/packages/requests/__init__.py:91: RequestsDependencyWarning: urllib3 (1.26.2) or chardet (4.0.0) doesn't match a supported version!
11-04-2021 11:08:22.831 +0100 ERROR ExecProcessor - message from "/opt/splunk/bin/python3.7 /opt/splunk/etc/apps/SplunkEnterpriseSecuritySuite/bin/import_icons_SplunkEnterpriseSecuritySuite.py" RequestsDependencyWarning)
What's interesting is that both python packages which are supposedly unsupported come with the ES app itself (are located in /opt/splunk/etc/apps/SplunkEnterpriseSecurity/lib/SplunkEnterpriseSecuritySuite_app_common/packages).
I'm not sure if it's the first ever occurence of this error because the only splunk components which have been restarted during the _internal retention period were HF's which obviously don't host ES.
I will be restarting my SH's later in the day so I expect the same errors there as well.
Has anyone encountered it? Should I simply fill a support ticket? (yes, we're a bit behind since it's a 6.4.1 but I don't see it as any known or fixed later issue)