# Buggy code
def _load(cls, leaderPath):
    bytesIO = BytesIO()
    with ZipFile(file=bytesIO, mode="w") as zipFile:
        for dirPath, fileNames, dirNames in os.walk(leaderPath):
            assert dirPath.startswith(leaderPath)
            for fileName in fileNames:
                filePath = os.path.join(dirPath, fileName)
                assert filePath.encode("ascii") == filePath
                relativeFilePath = os.path.relpath(filePath, leaderPath)
                assert not relativeFilePath.startswith(os.path.sep)
                zipFile.write(filePath, relativeFilePath)
    bytesIO.seek(0)
    return bytesIO


# 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 _load(cls, leaderPath):
    """
    :type leaderPath: str
    """
    bytesIO = BytesIO()
    # PyZipFile compiles .py files on the fly, filters out any non-Python files and
    # distinguishes between packages and simple directories.
    with PyZipFile(file=bytesIO, mode="w") as zipFile:
        zipFile.writepy(leaderPath)
    bytesIO.seek(0)
    return bytesIO