ERROR: Directory ‘/some/path’ exists but failed copying to ‘/some/other/path’

An error like this prevented my Jenkins build from completing. It was not a permissions issue. Jenkins was not configured with a master and slave.

My ‘/some/path’ source folder was empty.

In this case, PHPDox was failing silently and not outputting files. Another step in the build tried to move those files, but they didn’t exist so the build failed here. Fixing the malfunctioning build step (PHPDox in my case) resolved the issue and build 100% succeeded on the next try.