Q: Set custom path to executable with event plugin on submission?

Hmm… I wonder if you might have another event or script which is actually setting that value somewhere (using “=” instead of “+=”. You could try and read the name of the function out to get an idea what script had set it:

C:\>python
Python 3.6.1 (v3.6.1:69c0db5, Mar 21 2017, 17:54:52) [MSC v.1900 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> def hey():
...     print("hey")
...
>>> hey()
hey
>>> f = hey
>>> print(f)
<function hey at 0x03BD61E0>

I tested here with 10.0.21 (I’m a bit behind!) with the following code:

from Deadline.Scripting import *
from FranticX.Diagnostics import *

def AlterCommandLine( executable, arguments, workingDirectory ):
    print "Entering Command Line Hook"

    print "-----Modified Command Line-----"
    print " Executable: '{}'".format( executable )
    print "  Arguments: '{}'".format( arguments )
    print "Working Dir: '{}'".format( workingDirectory )
    print "-------------------------------"

    # return the original or modified exe, args, workingDir even if pipeline not available
    return (executable, arguments, workingDirectory)

def __main__( deadlinePlugin ):
    deadlinePlugin.DebugLogging = True
    deadlinePlugin.ModifyCommandLineCallback += AlterCommandLine

And the output was this guy:

2018-11-30 14:39:23:  0: PYTHON: Entering Command Line Hook
2018-11-30 14:39:23:  0: PYTHON: -----Modified Command Line-----
2018-11-30 14:39:23:  0: PYTHON:  Executable: 'C:\Users\amsler\Downloads\noexit\target\debug\noexit.exe'
2018-11-30 14:39:23:  0: PYTHON:   Arguments: ''
2018-11-30 14:39:23:  0: PYTHON: Working Dir: ''
2018-11-30 14:39:23:  0: PYTHON: -------------------------------