Workaround

If possible add a default value for the parameter like *

Details

Mapping setting: //depot/my-project/releases/${RELEASE}/... //my-project-release/...

Mar 14, 2012 12:17:36 PM hudson.plugins.perforce.PerforceSCM processWorkspaceBeforeDeletion
SEVERE: null
com.tek42.perforce.PerforceException: Error in client specification. Error detected at line 9. Null directory (//) not allowed in '//depot/my-project/releases//...'.
For Command: /usr/bin/p4 -s client -i
With Data:
===================
Client: my-project-release
Owner: perforce
Description: Created by perforce.
Root: opt/jenkins-data/jobs/my-project-release/workspace
Options: noallwrite clobber nocompress unlocked nomodtime rmdir
SubmitOptions: submitunchanged
LineEnd:
View:
//depot/my-project/releases//... //my-project-release/...

===================

at com.tek42.perforce.parse.AbstractPerforceTemplate.saveToPerforce(AbstractPerforceTemplate.java:261)
at com.tek42.perforce.parse.Workspaces.saveWorkspace(Workspaces.java:69)
at hudson.plugins.perforce.PerforceSCM.saveWorkspaceIfDirty(PerforceSCM.java:1373)
at hudson.plugins.perforce.PerforceSCM.processWorkspaceBeforeDeletion(PerforceSCM.java:2353)
at hudson.plugins.perforce.PerforceSCM.checkout(PerforceSCM.java:575)
at hudson.model.AbstractProject.checkout(AbstractProject.java:1195)
at hudson.model.AbstractBuild$AbstractRunner.checkout(AbstractBuild.java:579)
at hudson.model.AbstractBuild$AbstractRunner.run(AbstractBuild.java:468)
at hudson.model.Run.run(Run.java:1408)
at hudson.maven.MavenModuleSetBuild.run(MavenModuleSetBuild.java:481)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:238)