Running bash script in Post-Export method

I want to execute a bash script in OnPostProcessBuild() method , but my Unity Cloud build fails with below error logs :

! Unity player export failed!
! build of ‘default_-android’ failed. compile failed
Publishing build 22 of … for target ‘default_-android’…
publishing finished successfully.
done.
Build step ‘Execute shell’ marked build as failure
postbuildstatus finished successfully.
Finished: FAILURE

My Code is as below :

public class MyBuildPostprocessor : MonoBehaviour {

[PostProcessBuild]

public static void OnPostProcessBuild(BuildTarget target, string pathToBuiltProject) { 
   String[] pathArr = pathToBuiltProject.Split ('/'); 
String apkName = pathArr [pathArr.Length - 1]; 
String apkPath = pathToBuiltProject.TrimEnd (apkName.ToCharArray());
string scriptPath = Application.dataPath + "\\Plugins\\Android\\Editor\\PostProcessShellScript.sh\""; 
RunInShell("open","\"" + scriptPath + " " + " " + "\"" + apkPath + "\""+ "\\ " + apkName, false);
}
public static void RunInShell(string file, string args, bool waitForExit = true) { 	
System.Diagnostics.Process ppScriptProcess = new System.Diagnostics.Process(); 
ppScriptProcess.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Maximized; 
ppScriptProcess.StartInfo.FileName = file; 
ppScriptProcess.StartInfo.Arguments = args; 
ppScriptProcess.StartInfo.UseShellExecute = false; 
ppScriptProcess.StartInfo.CreateNoWindow = false; 
ppScriptProcess.StartInfo.RedirectStandardOutput = true;
  ppScriptProcess.Start();}}

+1 have same question no answers no examples short documentation hazy