InitialWorkDir listing with expression returning a directory: TypeError

initial-empty-directory.cwl
``` yaml
class: CommandLineTool
cwlVersion: v1.0
requirements:
- class: InlineJavascriptRequirement
- class: ShellCommandRequirement
- class: InitialWorkDirRequirement
listing: |
${return {'type': 'array', 'items': [ inputs.empty ]};}

inputs:
empty: Directory

outputs:
outlist: stdout

arguments: ["find", ".",
{shellQuote: false, valueFrom: "|"},
"sort"]
```

```
/home/michael/cwltool/env/bin/cwltool 1.0.20161110155008
Resolved 'initial-empty-directory.cwl' to 'file:///home/michael/common-workflow-language/v1.0/v1.0/initial-empty-directory.cwl'
Parsed job order from command line: {
"id": "initial-empty-directory.cwl",
"empty": {
"class": "Directory",
"location": "file:///home/michael/common-workflow-language/v1.0/v1.0/empty"
},
"job_order": null
}
[job initial-empty-directory.cwl] initializing from file:///home/michael/common-workflow-language/v1.0/v1.0/initial-empty-directory.cwl
[job initial-empty-directory.cwl] {
"empty": {
"basename": "empty",
"listing": [],
"class": "Directory",
"location": "file:///home/michael/common-workflow-language/v1.0/v1.0/empty"
},
"job_order": null
}
[job initial-empty-directory.cwl] path mappings is {
"file:///home/michael/common-workflow-language/v1.0/v1.0/empty": [
"file:///home/michael/common-workflow-language/v1.0/v1.0/empty",
"/tmp/tmp61L6Oy/stga03dfc90-d052-48d8-8438-888bdbf30616/empty",
"Directory"
]
}
[job initial-empty-directory.cwl] command line bindings is [
{
"position": [
0,
0
],
"datum": "find"
},
{
"position": [
0,
1
],
"datum": "."
},
{
"shellQuote": false,
"position": [
0,
2
],
"valueFrom": "|"
},
{
"position": [
0,
3
],
"datum": "sort"
}
]
[job initial-empty-directory.cwl] /tmp/tmpQmQtpz$ /bin/sh \
-c \
'find' '.' | 'sort' > /tmp/tmpQmQtpz/62560fea-6a41-4d73-9b2d-9665b454f832
Exception while running job
Traceback (most recent call last):
File "/home/michael/cwltool/env/local/lib/python2.7/site-packages/cwltool/job.py", line 232, in run
self.outdir, separateDirs=False)
File "/home/michael/cwltool/env/local/lib/python2.7/site-packages/cwltool/pathmapper.py", line 141, in __init__
self.setup(dedup(referenced_files), basedir)
File "/home/michael/cwltool/env/local/lib/python2.7/site-packages/cwltool/pathmapper.py", line 181, in setup
self.visit(fob, stagedir, basedir)
File "/home/michael/cwltool/env/local/lib/python2.7/site-packages/cwltool/pathmapper.py", line 157, in visit
self.visitlisting(obj.get("listing", []), tgt, basedir)
File "/home/michael/cwltool/env/local/lib/python2.7/site-packages/cwltool/pathmapper.py", line 146, in visitlisting
tgt = os.path.join(stagedir, ld["basename"])
TypeError: string indices must be integers
[job initial-empty-directory.cwl] completed permanentFail
[job initial-empty-directory.cwl] {}
Final process status is permanentFail
[job initial-empty-directory.cwl] Removing input staging directory /tmp/tmp61L6Oy
[job initial-empty-directory.cwl] Removing temporary directory /tmp/tmpCX1r9v
[job initial-empty-directory.cwl] Removing empty output directory /tmp/tmpQmQtpz
Workflow error, try again with --debug for more information:
Process status is ['permanentFail']
Traceback (most recent call last):
File "/home/michael/cwltool/env/local/lib/python2.7/site-packages/cwltool/main.py", line 710, in main
**vars(args))
File "/home/michael/cwltool/env/local/lib/python2.7/site-packages/cwltool/main.py", line 238, in single_job_executor
raise WorkflowException(u"Process status is %s" % (final_status))
WorkflowException: Process status is ['permanentFail']
```