I probably should have chimed in this bit earlier:
I can execute the script just fine manually on the MangoES by running:
/home/mango/shell_name.sh virtualEnv "python script_name.py arg1 arg2"
Unfortunately the tokenizing of the process event handler is not the same as the shell that it will pass the arguments to. Quotes and subshells are ignored. The Process Event Handler will pass a list of space delimited strings as arguments to whatever is the first argument.
cat 'hello.txt' and the error I get is:
Process error: 'cat: 'Hello.txt': No such file or directory cat.
Assuredly the cause of this is the single quotes are ignored as shell markup and tokenized into the first argument passed to cat, and there is no file named
Edit: Note that this is not the case when using the SSH Data Source, where all subshells and quotes and whatnot should be honored appropriately.