n1k0/casperjs — pull request #875 by ProdigySim (2014-04-07 18:36:37+00:00)
Title: Use subprocess.call instead of os.exec to launch casperjs

Using os.exec on Windows causes the process to fork into the background--meaning that a command line environment running casperjs will not be able to read the return code or easily detect when the script has finished execution.

subprocess.call provides better cross-platform compatibility, and fixes the problem easily.