I often receive installer issues in "Custom Tools Plugin", which complain about "Run Command" behavior. Seems that its name and documentation are quite confusing, so I propose to slightly refactor them.

An original issue from James Hancox:

When I try to use the custom tools plugin to install a tool named "VxrAnt", I get the following error message:

Started by user anonymous
[CustomTools] - VxrAnt: Starting installation
[VxrAnt] $ sh -e D:\projects\tools\com.cloudbees.jenkins.plugins.customtools.CustomTool\VxrAnt\hudson7649328509533676101.sh
The system cannot find the file specified
FATAL: Cannot run program "sh" (in directory "D:\projects\tools\com.cloudbees.jenkins.plugins.customtools.CustomTool\VxrAnt"): CreateProcess error=2, The system cannot find the file specified
java.io.IOException: Cannot run program "sh" (in directory "D:\projects\tools\com.cloudbees.jenkins.plugins.customtools.CustomTool\VxrAnt"): CreateProcess error=2, The system cannot find the file specified
at java.lang.ProcessBuilder.start(Unknown Source)
at hudson.Proc$LocalProc.<init>(Proc.java:244)
at hudson.Proc$LocalProc.<init>(Proc.java:216)
at hudson.Launcher$LocalLauncher.launch(Launcher.java:773)
at hudson.Launcher$ProcStarter.start(Launcher.java:353)
at hudson.Launcher$RemoteLaunchCallable.call(Launcher.java:998)
at hudson.Launcher$RemoteLaunchCallable.call(Launcher.java:965)
at hudson.remoting.UserRequest.perform(UserRequest.java:118)
at hudson.remoting.UserRequest.perform(UserRequest.java:48)
at hudson.remoting.Request$2.run(Request.java:326)
at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at hudson.remoting.Engine$1$1.run(Engine.java:63)
at java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified
at java.lang.ProcessImpl.create(Native Method)
at java.lang.ProcessImpl.<init>(Unknown Source)
at java.lang.ProcessImpl.start(Unknown Source)
... 16 more

As my install script does not call sh, I can only assume that this is part of the internal workings of the custom tools plugin which has gone awry.