Create a job on a *nix system with a colon : in the name.
When the job tries to run ant it gets an error like:

FATAL: command execution failed
java.io.IOException: Cannot run program "/opt/apache-ant-1.7.0/bin/ant" (in
directory "/opt/webserver7/.hudson/jobs/what:IsGoingOn/workspace\client"):
error=2, No such file or directory

Notice the \ near the end of the path.
I'm using 1.149.