Allow version regex to match 4.0.stable.arch_linux

[ttencate]

Also leverage named capture groups and verbose regex mode for slightly more readability.

[ttencate]

Yes, this removal is on purpose. I don't see why we need to reject this form.

[Bromeon]

See discussion in #118. Eventually we should probably accept them, but require manual mapping, warning, etc. Maybe the easiest approach for this would be parsing the version into something like:

enum GodotVersion {
    Release{major, minor, patch},
    Git{sha},
    Unknown
}

There's of course a separate discussion to be had whether we should still support alpha/beta/rc now, but at least rc can still occur before minor releases. And since such binaries may still exist, we might want to detect them, to provide more helpful errors. It also separates the version parsing from any semantic implications.

[Bromeon]

[^.] might be better constrained as [a-z_], to not capture numbers and special characters.

Why is the whole group repeating? I'd rather make sure we know what the format looks like (and extract more information to be useful when finding compatibility), rather than "consume whatever group comes next"...

[ttencate]

See how the version string is built up. Turns out my regex captures the format quite well, but this was entirely by accident :)

A version string like 4.0.stable.foo.bar.baz-1.2.3.mono.mybuild.abcde1234 is actually valid, and can happen if people create their own custom build or link in third-party modules.

[Bromeon]

Thanks a lot for analyzing this! We should probably document this format somewhere... just where?

I also saw now that you used +?, the lazy operator -- so the Git revision afterwards should always be parsed correctly, if available?

Maybe it makes sense to add some exotic versions to the tests 🙂

[ttencate]

Based on my analysis, I even made the status (formerly stability) field accept [^.]+. Though we parse it explicitly, we currently don't use it anyway.

Added a comment linking to #118 (comment) so it's documented at least somewhere. Also expanded the comments inside the regex (yay for verbose regex syntax).

[Bromeon]

I'll merge this for now, but since this relaxes the version detection which makes compatibility detection harder (see #118), I may soon introduce some restrictions on the version again.

Thanks a lot for this, especially the readable regexes!
bors r+

[bors]

Build failed:

• full-ci

[ttencate]

Looks like debug builds on MacOS output some additional debug cruft that throws off the parser:

arguments
0: /Users/runner/work/_temp/godot_bin/godot.macos.editor.dev.x86_64
1: --version
Current path: /Users/runner/work/gdext/gdext/godot-core
4.1.dev.custom_build.79454bfd3

I'll see what I can do.

[Bromeon]

Looks like this was accepted under the old regex though? Maybe erroneously? 🤔

It's possible that we should build the Godot binary with a special configuration on macOS.

---

Btw, found a nice hack to format the regex on GitHub -- use Python highlighting 🙂

        r#"(?x) # ignore whitespace and allow line comments (starting with `#`)
        ^
        (?P<major>\d+)
        \.(?P<minor>\d+)
        # Patch version is omitted if it's zero.
        (?:\.(?P<patch>\d+))?
        # stable|dev|alpha|beta|rc12|... Can be set through an env var when the engine is built.
        \.(?P<status>[^.]+)
        # Capture both module config and build, could be multiple components:
        # mono|official|custom_build|gentoo|arch_linux|...
        # Notice +? for non-greedy match.
        (\.[^.]+)+?
        # Git commit SHA1, currently truncated to 9 chars, but accept the full thing
        (?:\.(?P<custom_rev>[a-f0-9]{9,40}))?
        $
    "#,

[ttencate]

Reported godotengine/godot#74906 upstream, and added a workaround.

[ttencate]

Looks like this was accepted under the old regex though? Maybe erroneously? 🤔

The old one had no anchors, so we're being a bit stricter here, to make sure we don't parse only a partial version if the rest doesn't conform to our assumptions.

[Bromeon]

bors r+

[bors]

Build succeeded:

• full-ci