My windows/mac jobs ran fine. For building some Botan lib on macOS slave, i had to upgrade Xcode, then macOS from macOS 10.10 to 10.13.
Afterwards, i noticed that the jenkins job build fails with the error 'no output for p4'.
In pre-build i execute p4 commands ok (correct output), but all of a sudden Jenkins then performs p4 workspace -o <workspace> 
and this fails with error 
Caught exception communicating with perforce. No output for: p4 workspace -o ...

That command runs fine when run from terminal command window on mac slave; apparently not within Jenkins job.

>>>>
12:09:40 Using remote perforce client: <workspace name>
12:09:40 [<computername>] $ p4 workspace -o <workspace name>
12:09:40 Caught exception communicating with perforce. No output for: p4 workspace -o <workspace name> com.tek42.perforce.PerforceException: No output for: p4 workspace -o <workspace name>
12:09:40 at com.tek42.perforce.parse.AbstractPerforceTemplate.getPerforceResponse(AbstractPerforceTemplate.java:409)
12:09:40 at com.tek42.perforce.parse.AbstractPerforceTemplate.getPerforceResponse(AbstractPerforceTemplate.java:302)
12:09:40 at com.tek42.perforce.parse.Workspaces.getWorkspace(Workspaces.java:61)
.....
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