Thanks for the citations! Reading this, it's semver-ish for sure; that said, the "ish" is exactly why we're doing this. I'll try to figure out how to get in touch with someone.
Hi Steve, I've looked at this relatively carefully, and I believe that Go does 100% follow the semver spec (modulo any bugs in the implementation).
However, while that happens to be my personal belief, I am not any type of world-class semver expert, nor am a semver maintainer, and hence always happy to learn more (especially from, say, an actual semver maintainer such as yourself ;-)
I think you are saying "-ish" in your comment above at least partly based the two chunks of linked code above, including this comment there:
// This package follows Semantic Versioning 2.0.0 (see semver.org)
// with two exceptions. First, it requires the "v" prefix. Second, it recognizes
// vMAJOR and vMAJOR.MINOR (with no prerelease or build suffixes)
// as shorthands for vMAJOR.0.0 and vMAJOR.MINOR.0.
It is true that Go treats the leading "v" as a requirement for VCS tags to be recognized as encoding a semantic version. That said, as far as I am aware, requiring the "v" prefix for VCS tags is allowed by the semver spec, and it might be possible to draw a distinction between a semver version (which does not include a "v") vs. how a given semver version is encoded into a VCS tag (where an encoding is allowed to include a "v", as far as I am aware). For example, there is an FAQ that was added a few years ago to 'master' at github.com/semver/semver that seemed to address this:
prefixing a semantic version with a "v" is a common way (in English) to indicate it is a version number. Abbreviating "version" as "v" is often seen with version control. Example: git tag v1.2.3 -m "Release version 1.2.3", in which case "v1.2.3" is a tag name and the semantic version is "1.2.3".[1]
I am also aware that a leading "v" vs. no leading "v" for VCS tags can trigger some impassioned debate, so I might regret posting this comment. ;-)
Regarding the second piece from that comment above -- that particular Go package does have the ability to parse something like "v1" or "v1.2" (without the three integers required by semver). However, the result is not interpreted as a valid semver version by the overall 'go' tool. For example, a VCS tag such as "v1.2" that the 'go' tool finds on a git repository will _not_ be interpreted as a semantic version (because it does not have the required three integers). However, being able to parse something like "v1" or "v1.2" is used for example as part of a version query mechanism. For example, you can do something like "go get foo@v1.2" as a way of asking "please give me the highest available release version in >= v1.2.0 and < v2.0.0". In other words, it is a short-hand for a particular type of version query, which I would guess would not be in violation of the current semver 2.0 spec? If interested, there is some more information about that query mechanism (which is called a "module query") in the Go doc[2].
Finally, here is a snippet from the Go doc[3] stating semver is used (and there is a link to https://semver.org in that section as well):
The go command requires that modules use semantic versions and expects that the versions accurately describe compatibility
I wouldn't be shocked if you have a different take on some or all of what I said above, but wanted to at least share my personal understanding...
So, primarily I am saying "ish" for two reasons: one, as I said below, I mis-understood how versions were actually used within Go. There's a lot of stuff out there, and keeping the three or four implementations I do know well is tough enough. Second, I don't want to say, definitively, that any particular implementation "does not implement Semver", because I think the spec is deficient enough that it's really hard to say in general.
On to your specific points:
> That said, as far as I am aware, requiring the "v" prefix for VCS tags is allowed by the semver spec
This is true, SemVer says nothing about VCSes.
> However, being able to parse parse something like "v1" or "v1.2" is used for example as part of a version query mechanism.
Right, so that's what I thought this was getting at, and the general "range" concept isn't in the spec, so all of that is fine, spec speaking.
However, that doc comment describes it a bit differently than you are. It describes them as version numbers. So it's possible that the doc comment is a bit mis-leading, maybe. That's very reasonable! This is why we need to clean up the spec text.
Makes sense. I guess the way I would summarize it is I believe the end-to-end Go system is 100% compliant with semver 2.0 spec. (And that is true to my knowledge even though there happens to be an internal-only 'semver' package that also contains Go-specific functionality related to semver, and that internal 'semver' package both must be used properly and is used properly to keep the overall end-to-end system semver spec compliant, including proper use of functions like isSemverPrefix(version) and similar to differentiate between what is allowed in a semver VCS tag vs. what is allowed for what is effectively a range-based query, etc.).
Both of these things are not deal breakers; some semver implementations do allow the prefix "v" (though none require, and some don't allow it too), and their other modification to version numbers is sort of what is done in some parts of the other implementations do. And as I said elsewhere, the matchers aren't part of today's spec, so it feels weird to disqualify them based on a sparse implementation.
My real point is that because the spec is incomplete, many of these kinds of questions cannot be answered, even within the big implementations. So I'm saying "ish" to hedge. Given the anti-SemVer tone throughout the vgo discussion, I thought they had gotten further away from the mainstream than they actually ended up, which is my mistake.
I think the initial vgo discussion and versioned Go modules proposal effectively said "developers expect semver; semver is helpful; Go is officially adopting and requiring semver". At the same time, I think there was also some discussion around "semver alone is not a complete answer". I can see how some of that might have been read as anti-semver, though I suspect that was not the intent.
In any event, it is exciting to see more energy going into the semver spec!
