Debug locust using VS code (PTVS). Just go to debug, add a debug configuration, select "python file" and run it when standing in the locust script.

debugging_locust.py

if __name__ == "__main__":
    with open("enable_gevent_debugging.py", "r") as myfile:
        exec(myfile.read())  # pylint: disable=W0122

from locust import HttpLocust, TaskSet, task


class WebTaskSet(TaskSet):
    @task
    def asdf(self):
        self.client.post("/myurl")
        # just do one iteration
        if __name__ == "__main__":
            exit(0)


class DebuggingLocust(HttpLocust):
    task_set = WebTaskSet
    host = "http://myserver"


# if someone runs just this script (not using locust -f ...), just spawn a single locust directly
if __name__ == "__main__":
    x = DebuggingLocust()
    x.run()

enable_gevent_debugging.py

# Gevent hangs during monkey patching when a debugger is attached
# Source this file before importing locust when you want to use a debugger
# Original code by ayzerar at https://github.com/Microsoft/PTVS/issues/2390

from gevent import monkey

monkey.patch_all()


def setup_ptvsd(host="0.0.0.0", port=5678):
    import sys

    saved_modules = {}
    try:
        green_modules = set(
            [
                "socket",
                "ssl",
                "select",
                "urllib",
                "thread",
                "threading",
                "time",
                "logging",
                "os",
                "signal",
                "subprocess",
                "requests",
            ]
        )
        for modname in list(sys.modules.keys()):
            if modname.partition(".")[0] in green_modules:
                saved_modules[modname] = sys.modules.pop(modname)

        import ptvsd  # pylint: disable=W0611

        ptvsd.enable_attach(address=(host, port), redirect_output=False)
    finally:
        sys.modules.update(saved_modules)


setup_ptvsd()