If the cleartool command is empty (or doesnt exist) then a fatal error should be
shown and not an exception.

Creating a snapshot clear tool
[workspace] $ mkview -snapshot -tag hudson_server_view hudson_server_view
FATAL: CreateProcess: mkview -snapshot -tag hudson_server_view
hudson_server_view error=2
java.io.IOException: CreateProcess: mkview -snapshot -tag
hudson_server_view hudson_server_view error=2
at java.lang.ProcessImpl.create(Native Method)
at java.lang.ProcessImpl.<init>(ProcessImpl.java:81)
at java.lang.ProcessImpl.start(ProcessImpl.java:30)
at java.lang.ProcessBuilder.start(ProcessBuilder.java:451)
at hudson.Proc$LocalProc.<init>(Proc.java:80)
at
hudson.Launcher$LocalLauncher.createLocalProc(Launcher.java:290)
at hudson.Launcher$LocalLauncher.launch(Launcher.java:281)
at
hudson.plugins.clearcase.ClearCaseSCM$ClearToolLauncherImpl.run(ClearCaseSCM.java:266)

at
hudson.plugins.clearcase.ClearToolSnapshot.mkview(ClearToolSnapshot.java:38)

at
hudson.plugins.clearcase.ClearCaseSCM.checkout(ClearCaseSCM.java:145)
at
hudson.model.AbstractProject.checkout(AbstractProject.java:529)
at
hudson.model.AbstractBuild$AbstractRunner.checkout(AbstractBuild.java:223)
at
hudson.model.AbstractBuild$AbstractRunner.run(AbstractBuild.java:189)
at hudson.model.Run.run(Run.java:646)
at hudson.model.Build.run(Build.java:102)
at
hudson.model.ResourceController.execute(ResourceController.java:70)
at hudson.model.Executor.run(Executor.java:62)