Thanks for submitting the issue! I'm all for a better error message 👍

hey @felix-hilden, i would like to work on this, and add the grammar version to the error message.
i believe the error occurs in src/black/parsing.py:103:

grammars = get_grammars(set(target_versions))
    errors = {}
    for grammar in grammars:
        drv = driver.Driver(grammar)
        try:
            result = drv.parse_string(src_txt, True)
            break

        except ParseError as pe:
            lineno, column = pe.context[1]
            lines = src_txt.splitlines()
            try:
                faulty_line = lines[lineno - 1]
            except IndexError:
                faulty_line = "<line number missing in source>"
            errors[grammar.version] = InvalidInput(
                f"Cannot parse: {lineno}:{column}: {faulty_line}"  # 103
            )

could you assign me?
thanks 😄

I think this issue should be marked closed, correct me if I am wrong

I think this issue should be marked closed, correct me if I am wrong

hey, usually an issue is closed when a PR is merged. this is done automatically if the PR contains something like closes #3294.

ok, cool. Looks like it's left for a pending reviewer to take a look

Hi @plannigan, I would like to work on this issue could you please assign me this.

We don't usually assign issues. If you have a suggested solution, please open a PR and we'll take a look.

I also don't have permissions to assign people to issues 😄.

hey guys, i offered a solution to this issue last year:
#3323

alas - it was disapproved, despite the fact that it fixed this issue.
please consider checking my PR again.
otherwise, if this issue is a won't fix, i recommend closing this issue.
thanks

I might try a new approach to this.

I've had another go at this, taking into account the feedback for the previous PR.

I was looking into the second part of the request about noting that syntax could be valid across other target versions, and I'm unable to reproduce this issue. As far as I can see, this error only occurs if ALL versions are unable to parse the line, so we shouldn't need this error to handle a case where some versions parse and others don't.

Given how old the ticket is, I don't remember exactly what the originally configured python versions were. But I feel like the content under "Describe alternatives you've considered" was more of "maybe X is happening" rather than "I know X is happening". So if there are different/better error messages when one configured parser can parse, but a different configured parser can't, then that is fine with me.

Unless there's a bigger issue here, I don't believe raising a parse error when one version parses and another does not is expected behaviour. Currently, there's a loop that stores errors and only raises the exception if all versions fail.

The pull request I've submitted will change the error message to look like this:

I think this should make it much clearer what is causing the error. If Black is parsing with a different version than what the user intended, this error should make them aware. Based on the feedback in the previous unsuccessful PR, I've included both the grammars and the Python versions. This should clarify the issue if a user requests a version that supports a feature but Black selects a grammar version that does not support the feature.