# Buggy code
def _check_conflict(cls, dirPath, name):
    """
    Check whether the module of the given name conflicts with another module on the sys.path.

    :param dirPath: the directory from which the module was originally loaded
    :param name: the mpdule name
    """
    old_sys_path = sys.path
    try:
        sys.path = [
            dir
            for dir in old_sys_path
            if os.path.realpath(dir) != os.path.realpath(dirPath)
        ]
        try:
            colliding_module = importlib.import_module(name)
        except ImportError:
            pass
        else:
            raise RuntimeError(
                "The user module '%s' collides with module '%s from '%s'."
                % (name, colliding_module.__name__, colliding_module.__file__)
            )
    finally:
        sys.path = old_sys_path


# Traceback (ImportError)
INFO:toil.batchSystems.mesos.batchSystem:Preparing to launch Mesos task 0 using offer 20151120-222317-83886090-5050-35148-O5...
INFO:toil.batchSystems.mesos.batchSystem:...launching Mesos task 0
WARNING:toil.leader:The jobWrapper seems to have left a log file, indicating failure: 46c1efec_0849_4ce3_b74d_c74f1f0602a4
WARNING:toil.leader:Reporting file: 46c1efec_0849_4ce3_b74d_c74f1f0602a4
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:       ---TOIL WORKER OUTPUT LOG---
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:       Traceback (most recent call last):
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:         File "/usr/local/lib/python2.7/dist-packages/toil/worker.py", line
266, in main
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:           job = Job._loadJob(jobWrapper.command, jobStore)
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:         File "/usr/local/lib/python2.7/dist-packages/toil/job.py", line 936, in _loadJob
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:           userModule = cls._loadUserModule(userModule)
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:         File "/usr/local/lib/python2.7/dist-packages/toil/job.py", line 914, in _loadUserModule
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:           return importlib.import_module(userModule.name)
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:         File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:           __import__(name)
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:         File "/tmp/tmpflu3Jl/5b3f3d5ba2a95124e308998df2ab7bb2/parallelMappingEvaluation.py", line 16, in <module>
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:           from toillib import *
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:       ImportError: No module named toillib
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:       Exiting the worker because of a failed jobWrapper on host c4agent1
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:       ERROR:toil.worker:Exiting the worker because of a failed jobWrapper on host c4agent1
WARNING:toil.leader:46c1efec_0849_4ce3_b74d_c74f1f0602a4:       WARNING:toil.jobWrapper:Due to failure we are reducing the remaining retry count of job 46c1efec_0849_4ce3_b74d_c74f1f0602a4 to 0
WARNING:toil.leader:Job: 46c1efec_0849_4ce3_b74d_c74f1f0602a4 is completely failed

# Fixed code
def _check_conflict(cls, dirPath, name):
    """
    Check whether the module of the given name conflicts with another module on the sys.path.

    :param dirPath: the directory from which the module was originally loaded
    :param name: the mpdule name
    """
    old_sys_path = sys.path
    try:
        sys.path = [
            d for d in old_sys_path if os.path.realpath(d) != os.path.realpath(dirPath)
        ]
        try:
            colliding_module = importlib.import_module(name)
        except ImportError:
            pass
        else:
            raise ResourceException(
                "The user module '%s' collides with module '%s from '%s'."
                % (name, colliding_module.__name__, colliding_module.__file__)
            )
    finally:
        sys.path = old_sys_path