Initially reported downstream: python-jsonschema/check-jsonschema#577

This pattern reads as a range from \d to /:

Maybe it works in some engines, but it definitely fails in Python. re.compile(r"^[a-z][a-z\\d-\/_]*$") gets an error:

re.error: bad character range d-\/ at position 12

I would tend to move - to the end of a character class so that it cannot be interpreted as a range. I'll submit a PR with that fix.