Re: [gentoo-dev] dev-lang/go

[Jan Matejka]

On Thu, 13 Feb 2014 11:59:16 -0600
William Hubbs <williamh@g.o> wrote:

> Hi all,
>
> I responded to this a while back, but I guess my email didn't go out
> for some reason.
>
> As the primary go maintainer, I do want to be involved in this. :-)
>
> On Tue, Feb 11, 2014 at 01:38:44AM +0100, yac wrote:
> > On Mon, 30 Dec 2013 15:48:17 -0500
> > Emery Hemingway <emery@×××××××.net> wrote:
> >
> > > I really like working with Go, and would like to see a means of
> > > merging Go packages with Portage. In short I am asking if anyone
> > > else is interested in a Go project.
> >
> > I might be. I have packaged something for private use but it just a
> > bunch of hacks. Anyway, I have some production go code.
> >
> > >
> > > For those who aren't familiar with Go, I will sumarise why
> > > Portage and Go do not play well together.
> > >
> > > Go is static linked by default.
> > > The Go compiler creates static libraries and binaries. Libraries
> > > compilied with different versions of Go (1.1/1.2) may not be
> > > linked into the same binary.
> >
> > Haskell is staticaly linked as well (by default) and you can see the
> > gentoo haskell project. I don't see this as a problem, we just will
> > have all dependencies in DEPEND and will have to scope on the go
> > compiler version under something like /usr/lib/go-1.{1,2}/...
>
> That could be done easily enough, but what about the tools in /usr/bin
> (there aren't many, but there are a couple), and these do not change
> name with each version of go.

Please see what python does for different python versions (which you
omitted from my previous email).

> > > Go libraries are usually unversioned.
> > > Libraries outside the system library are resolved with an import
> > > statement that specifies a source code repository, such as a git
> > > or mecurial repository. Most often Go libraries are installed
> > > using the 'go get' tool that clones a repository, and simply
> > > assumes HEAD/tip is the best revision to build against. There is
> > > some support for using git tags but it is not well documented.
> > > Often these libraries are very small for the sake of reuse and to
> > > keep APIs simple.
>
> My understanding is that a library repo will have branches based on
> the version of go, so for example, it might have a branch called go-1
> which will be where go get will look to find the latest version of
> the code that works with go-1.x.
>
> > In this case we just have to require upstream to make releases or
> > publish either live ebuilds, or ebuilds versioned something like
> > 0_preYYYY-MM-DD.ebuild [1]
>
> I don't think we are going to be able to require upstream to make
> releases, so that leaves us with:
>
> 1) using live ebuilds, which will never be allowed to have keywords by
> gentoo policy, or
> 2) publishing snapshots, which also means we have to create tarballs
> to match them. This will be a lot of work for us as maintainers.
> Also, the only way we will know when a new "version" of the library
> is released is to closely monitor the upstream git repository.

As I said in previous email, I think at least part of go community sees
this as an issue and this is something we can not solve right now but
rather need to work on this on case-by-case basis.

Some upstreams may be willing to do releases / follow semver.org or
something like that. But there will also be upstream which won't and
that's fine, we should be able to handle both cases.

Anyway, asking the upstream to do a release is simple enough and you
won't know until you ask.
 
> The other concern, which I believe zero was talking about is, once a
> library is installed in GOPATH, I don't think the go build system
> rebuilds it. In other words, "go get" will see that it is already
> there and I don't think it goes back out to the net to check for any
> changes.

I think when doing a `go build` it will check if newer version is
available and print a warning.

> William
>



--
Jan Matějka        | Gentoo Developer
https://gentoo.org | Gentoo Linux
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