Parens in metadata version specifiers

[jaklaassen-affirm]

The packaging spec says that Requires-Dist specifiers should not have parens, but wheel add the parens here.

I ran into this problem because of a super edge case installing a wheel that has exact identity (===) dependencies. Pip allows any character after an the identity specifier, which means that it also captures the closing paren and so a requirement like requests (===1.2.3) won't match. The identity specifiers are used for prereleases and some other special-case version specifiers.

[henryiii]

Looks like it says:

A version specifier. Tools parsing the format should accept optional parentheses around this, but tools generating it should not use parentheses.

So the parentheses shouldn’t be generated but should still be accepted.

[jaklaassen-affirm]

Agreed, and this is imo both a pip and a wheel bug. The wheel bug is arguably not because it still should work according to the spec. The pip bug just looked harder to fix given the implementation, but I didn't check whether their vendored copy of packaging was out of date. And indeed it is. Packaging has switched from a regex-only to a tokenizing parser that successfully handles the identity requirements in parens. So pip just needs to update the vendored version. Although that appears to be quite complicated.

[agronholm]

I'm ready to cut a new release once the linked PR is okayed.

[agronholm]

Released.