Our pipeline build shares the workspace to avoid a disk space crisis:

    node(label) {
      ws(getCustomWorkspace()) {

The build does use the specified workspace, but it's impossible to navigate to it from the Jenkins GUI.

Example URL for one step page:

http://_buildserver_/job/pipeline-github/job/core/view/change-requests/job/PR-50/29/execution/node/16/

The page says:

Running on W-Buildslave05 in H:\hudson\workspace\pipeline-github_core_PR-50-KZXDVTLM6IYU3ZK3N7DWU5QR4ODL5DU2UGPV2PS5G6WFQGQE5XIQ

If I go to the build slave in question, the directory doesn't actually exist.

The link in the sidebar links to:

http://_buildserver_/job/pipeline-github/job/core/view/change-requests/job/PR-50/29/execution/node/16/ws

But Jenkins gives a 404 for that URL.

Given that it gives a 404, it might not be the custom workspace which causes the issue... but it seems to be the only thing we've customised, and you'd think that if it's a deeper problem, someone who isn't using a custom workspace would have noticed it by now.