in the python console the following statement works perfectly fine (i guess using eval that way is not really good, but its just for testing purpose in this case and will be replaced with proper parsing) $ python >>> import subprocess >>> r = subprocess.Popen(['/home/kupferwerk/sd-agent-plugins/plugin1.rb'], stdout=subprocess.PIPE, close_fds=True).communicate()[0] >>> data = eval(r) >>> data {'test': 1} when i convert this into a Serverdensity plugin however it keeps crashing the agent.py daemon everytime it executes the plugin. i was able to narrow it down to the subprocess line but could not find out why. exception catching did not seem to work also. here how the plugin looks like: class plugin1: def run(self): r = subprocess.Popen(['/pathto/plugin1.rb'], stdout=subprocess.PIPE, close_fds=True).communicate()[0] data = eval(r) return data I'm quite new to work with python and cant really figure out why this wont work. Thanks a lot for ideas :)