schemasheets doesn't seem to instantiate mixins yet about schemasheets

[turbomam]

Traceback (most recent call last):
File "/Users/MAM/Library/Caches/pypoetry/virtualenvs/sheets-and-friends-XU_YBljG-py3.9/bin/sheets2linkml", line 8, in
sys.exit(convert())
File "/Users/MAM/Library/Caches/pypoetry/virtualenvs/sheets-and-friends-XU_YBljG-py3.9/lib/python3.9/site-packages/click/core.py", line 1128, in call
return self.main(*args, **kwargs)
File "/Users/MAM/Library/Caches/pypoetry/virtualenvs/sheets-and-friends-XU_YBljG-py3.9/lib/python3.9/site-packages/click/core.py", line 1053, in main
rv = self.invoke(ctx)
File "/Users/MAM/Library/Caches/pypoetry/virtualenvs/sheets-and-friends-XU_YBljG-py3.9/lib/python3.9/site-packages/click/core.py", line 1395, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/Users/MAM/Library/Caches/pypoetry/virtualenvs/sheets-and-friends-XU_YBljG-py3.9/lib/python3.9/site-packages/click/core.py", line 754, in invoke
return __callback(*args, **kwargs)
File "/Users/MAM/Library/Caches/pypoetry/virtualenvs/sheets-and-friends-XU_YBljG-py3.9/lib/python3.9/site-packages/schemasheets/schemamaker.py", line 701, in convert
schema = sm.create_schema(list(tsv_files))
File "/Users/MAM/Library/Caches/pypoetry/virtualenvs/sheets-and-friends-XU_YBljG-py3.9/lib/python3.9/site-packages/schemasheets/schemamaker.py", line 213, in create_schema
self.merge_sheet(f, **kwargs)
File "/Users/MAM/Library/Caches/pypoetry/virtualenvs/sheets-and-friends-XU_YBljG-py3.9/lib/python3.9/site-packages/schemasheets/schemamaker.py", line 276, in merge_sheet
raise SchemaSheetRowException(f'Error in line {line_num}, row={row}') from e
schemasheets.schemamaker.SchemaSheetRowException: Error in line 5, row={'class': '', 'slot': '', 'description': 'a test mixin', 'mixin': 'test mixin'}

[turbomam]

@cmungall kindly reminded me that there's no such thing as a mixin element, only an element with the mixin attribute set to true.