Hello,

Right now, a quick 'grep -l github.*tarball' shows that there are about
147 ebuilds in portage using github snapshots. This evaluates to 83
different packages.

The problem with github is that it suffixes the tarballs with
a complete git commit id. This means that the `S' variable
in the ebuild needs to refer to a long hash changing randomly. Right
now, the problem is handled in a number of ways:

1) (from app-admin/rudy)

S="${WORKDIR}/solutious-${PN}-*"

I'm surprised if that actually works. I'd say that seems not
PMS-compliant but in fact PMS seems to almost not mention S.

2) (app-emacs/calfw and suggested solution for Sunrise)

src_unpack() {
	unpack ${A}
	mv kiwanami-emacs-calfw-* ${P} || die
}

3) (app-misc/bgrep)

GITHUB_USER="tmbinc"
GITHUB_HASH="49b098be9548d174023ad05c10f6af9d02b8e18e"
MY_P="${GITHUB_USER}-${PN}-${GITHUB_HASH:0:7}"
S="${WORKDIR}/${MY_P}"

4) (app-misc/tmux-mem-cpu-load)

src_prepare() {
	cd "${WORKDIR}"/thewtex-${PN}-*
	S=$(pwd)
}


What I'd like to do is creating a small github.eclass, encapsulating
a common, nice way of handling the S issue. I guess the best solution
would be to git with something like 2) above, with the eclass providing
github_src_unpack() for EAPIs 2+.

Maybe the eclass could be extended to support other kinds of snapshots.
I'm not sure if there aren't other services providing snapshots similar
to github.

-- 
Best regards,
Michał Górny