validate() produces exception when extensions are indicated

[gmabey]

For this python script:

#!/usr/bin/env python3

import numpy
import sigmf
global_info = {
        "core:author": "Glen M",
        "core:datatype": "ri16_le",
        "core:license": "https://creativecommons.org/licenses/by-sa/4.0/",
        "core:sample_rate": 48000,
        "core:version": "1.0.0",
        "core:extensions" : [
            { "name": "extension-01",
              "version": "0.0.5",
              "optional": True },
            { "name": "extension-02",
              "version": "1.2.3",
              "optional": False }
        ]
    }
capture_info = { "core:datetime": "2021-06-18T23:17:51.163959Z" }

base_filename = 'extensions_test'
meta_filename = base_filename + '.sigmf-meta'
data_filename = base_filename + '.sigmf-data'

numpy.arange(5, dtype=numpy.int16) .tofile(data_filename)
meta = sigmf.SigMFFile(data_file=data_filename, global_info=global_info)
meta.add_capture(0, metadata=capture_info)
meta.tofile(meta_filename, toarchive=True)

I get an exception thrown that I don't understand:

$ ./exercise_extensions.py  
Traceback (most recent call last):
  File "./exercise_extensions.py", line 29, in <module>
    meta.tofile(meta_filename, toarchive=True)
  File "/Users/glenm/src/SigMF/sigmf/sigmffile.py", line 545, in tofile
    self.archive(fns['archive_fn'])
  File "/Users/glenm/src/SigMF/sigmf/sigmffile.py", line 526, in archive
    archive = SigMFArchive(self, name, fileobj)
  File "/Users/glenm/src/SigMF/sigmf/archive.py", line 74, in __init__
    self._check_input()
  File "/Users/glenm/src/SigMF/sigmf/archive.py", line 111, in _check_input
    self._validate_sigmffile_metadata()
  File "/Users/glenm/src/SigMF/sigmf/archive.py", line 133, in _validate_sigmffile_metadata
    valid_md = self.sigmffile.validate()
  File "/Users/glenm/src/SigMF/sigmf/sigmffile.py", line 454, in validate
    return validate.validate(
  File "/Users/glenm/src/SigMF/sigmf/validate.py", line 154, in validate
    for result in (validate_section(data.get(key), ref.get(key), key) for key in ref):
  File "/Users/glenm/src/SigMF/sigmf/validate.py", line 154, in <genexpr>
    for result in (validate_section(data.get(key), ref.get(key), key) for key in ref):
  File "/Users/glenm/src/SigMF/sigmf/validate.py", line 145, in validate_section
    return {
  File "/Users/glenm/src/SigMF/sigmf/validate.py", line 108, in validate_section_dict
    for result in key_validation_results:
  File "/Users/glenm/src/SigMF/sigmf/validate.py", line 102, in <genexpr>
    validate_key(
  File "/Users/glenm/src/SigMF/sigmf/validate.py", line 78, in validate_key
    if 'type' in ref_dict and not match_type(data_value, ref_dict["type"]):
  File "/Users/glenm/src/SigMF/sigmf/validate.py", line 46, in match_type
    return value is None or {
KeyError: 'dict_list'

which you may recognize, since I copy-pasted the "core:extensions" list from the explanation given in sigmf-spec.md.

I plan to try to look into this error, but in the past validate() has been tricky ...

[gmabey]

this was duplicate to #186 filed by someone I know ...