Discovered because I've had an issue starting Internet Explorer on specific nodes passing 'jenkins:label' to the Selenium Plugin grid.
Exception in thread "main" org.openqa.selenium.SessionNotCreatedException: No matching capability sets found.
Unable to match capability set 0: jenkins:label is an unknown extension capability for IE
The w3c specification say for New Session says:
If the remote end is an intermediary node, it may use the result of the capabilities processing algorithm to route the new session request to the appropriate endpoint node.
An intermediary node is free to define extension capabilities to assist in this process, however, these specific capabilities must not be forwarded to the endpoint node.
⚠️ Fixing this properly will depend on feature request with selenium grid to add configuration for custom capabilities mutators #7478
Discovered because I've had an issue starting Internet Explorer on specific nodes passing 'jenkins:label' to the Selenium Plugin grid.
The w3c specification say for New Session says: