Arvados

2017-10-08_14:17:52 e51c5-8i9sb-xo9w8fidi304bcv 6764 0 stderr Unexpected error from fs_access
2017-10-08_14:17:52 e51c5-8i9sb-xo9w8fidi304bcv 6764 0 stderr Traceback (most recent call last):
2017-10-08_14:17:52 e51c5-8i9sb-xo9w8fidi304bcv 6764 0 stderr   File "/usr/lib/python2.7/dist-packages/cwltool/draft2tool.py", line 578, in collect_output
2017-10-08_14:17:52 e51c5-8i9sb-xo9w8fidi304bcv 6764 0 stderr     prefix = fs_access.glob(outdir)
2017-10-08_14:17:52 e51c5-8i9sb-xo9w8fidi304bcv 6764 0 stderr   File "/usr/lib/python2.7/dist-packages/arvados_cwl/fsaccess.py", line 86, in glob
2017-10-08_14:17:52 e51c5-8i9sb-xo9w8fidi304bcv 6764 0 stderr     patternsegments = rest.split("/")
2017-10-08_14:17:52 e51c5-8i9sb-xo9w8fidi304bcv 6764 0 stderr AttributeError: 'NoneType' object has no attribute 'split'

The branch right before this:

        if collection and not rest:
            return [pattern]
        patternsegments = rest.split("/")

We know rest is None

Seems that bool(collection) is False, this means collection must be None (?) Testing indicates that bool(collection) == True even when collection is empty.