cwltool --validate is success --make-template becomes failure

[manabuishii]

Expected Behavior

Output template something like this.

(cwlenv) ➜  create_issue cwltool --validate success.cwl     
INFO /home/manabu/work/CWL/create_issue/cwlenv/bin/cwltool 3.1.20231114134824
INFO Resolved 'success.cwl' to 'file:///home/manabu/work/CWL/create_issue/success.cwl'
success.cwl is valid CWL.
(cwlenv) ➜  create_issue cwltool --make-template success.cwl
INFO /home/manabu/work/CWL/create_issue/cwlenv/bin/cwltool 3.1.20231114134824
INFO Resolved 'success.cwl' to 'file:///home/manabu/work/CWL/create_issue/success.cwl'
params:  # array of "file:///home/manabu/work/CWL/create_issue/success.cwl#params/ParamPair" record type.
  - param2: a_string  # type 'string'
    param1: a_string  # type 'string'

Actual Behavior

No template output.

(cwlenv) ➜  create_issue cwltool --validate problem.cwl 
INFO /home/manabu/work/CWL/create_issue/cwlenv/bin/cwltool 3.1.20231114134824
INFO Resolved 'problem.cwl' to 'file:///home/manabu/work/CWL/create_issue/problem.cwl'
problem.cwl is valid CWL.
(cwlenv) ➜  create_issue cwltool --validate problem.cwl 
INFO /home/manabu/work/CWL/create_issue/cwlenv/bin/cwltool 3.1.20231114134824
INFO Resolved 'problem.cwl' to 'file:///home/manabu/work/CWL/create_issue/problem.cwl'
problem.cwl is valid CWL.
(cwlenv) ➜  create_issue cwltool --make-template problem.cwl
INFO /home/manabu/work/CWL/create_issue/cwlenv/bin/cwltool 3.1.20231114134824
INFO Resolved 'problem.cwl' to 'file:///home/manabu/work/CWL/create_issue/problem.cwl'
ERROR I'm sorry, I couldn't load this CWL file, try again with --debug for more information.
The error was: 0

Workflow Code

success.cwl

#!/usr/bin/env cwl-runner

cwlVersion: v1.2
class: CommandLineTool

inputs:
  params:
    type:
      type: array
      items:
        - type: record
          name: ParamPair
          fields:
            - name: param1
              type: string
            - name: param2
              type: string
outputs: []

baseCommand: []

problem.cwl

#!/usr/bin/env cwl-runner

cwlVersion: v1.2
class: CommandLineTool

inputs:
  params:
    type:
      type: array
      items:
        type: record
        name: ParamPair
        fields:
          - name: param1
            type: string
          - name: param2
            type: string
outputs: []

baseCommand: []

Full Traceback

(cwlenv) ➜  create_issue cwltool  --debug --make-template problem.cwl
INFO /home/manabu/work/CWL/create_issue/cwlenv/bin/cwltool 3.1.20231114134824
INFO Resolved 'problem.cwl' to 'file:///home/manabu/work/CWL/create_issue/problem.cwl'
ERROR I'm sorry, I couldn't load this CWL file.
The error was: 
Traceback (most recent call last):
  File "/home/manabu/work/CWL/create_issue/cwlenv/lib/python3.10/site-packages/cwltool/main.py", line 1135, in main
    make_template(tool, stdout)
  File "/home/manabu/work/CWL/create_issue/cwlenv/lib/python3.10/site-packages/cwltool/main.py", line 754, in make_template
    generate_input_template(tool),
  File "/home/manabu/work/CWL/create_issue/cwlenv/lib/python3.10/site-packages/cwltool/main.py", line 342, in generate_input_template
    value, comment = generate_example_input(inp["type"], inp.get("default", None))
  File "/home/manabu/work/CWL/create_issue/cwlenv/lib/python3.10/site-packages/cwltool/main.py", line 204, in generate_example_input
    example, comment = generate_example_input(inptype[0], default)
  File "/home/manabu/work/CWL/create_issue/cwlenv/lib/python3.10/site-packages/cwltool/main.py", line 222, in generate_example_input
    first_item = cast(MutableSequence[CWLObjectType], inptype["items"])[0]
  File "/home/manabu/work/CWL/create_issue/cwlenv/lib/python3.10/site-packages/ruamel/yaml/comments.py", line 851, in __getitem__
    return ordereddict.__getitem__(self, key)
KeyError: 0
(cwlenv) ➜  create_issue 

Your Environment

• cwltool version:
  Check using cwltool --version

(cwlenv) ➜  create_issue cwltool --version
/home/manabu/work/CWL/create_issue/cwlenv/bin/cwltool 3.1.20231114134824
(cwlenv) ➜  create_issue