Re: feature/package+vc 04c4c578c7 3/4: Allow for packages to be installed directly from VCS

[Stefan Monnier]

>> I'm thinking of things like the code that handles `:doc` or `:make`.
>> These don't care about Git.
> For something like :make to work, we would also require :renames, right?

No, it's done before renames.

> But if that is added, then the version control could break.

In the part of `elpa-admin.el` designed for "install from Git"
(i.e. the part that matches package+vc's goal), `:rename` is not taken
into account.  I don't think we can reasonably do so, as you point out,
so I think `:renames` should be labeled as something we can't support
(and eventually deprecated for that reason).

> How does this look like:

I'm a bit confused: it seems to do for `:core` what I expected to happen
for packages with a nil `:url` (and it doesn't drop `:core` packages,
like I'd expect).

Other than that, it looks OK (in the nitpick area, I'd move the code to
its own function and then call it from `elpaa-batch-make-all-packages`).

I like the `.eld` extension, and I guess "elpa-packages.eld" is as good
a name as any.

> It currently makes the assumption that :core is the first element in the
> property list for each package specification.

That's right: that element should be either `:core` or `:url`.


        Stefan