bug#45345: [elpa-archive] "make build/<package>" should not pull unconditionally

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> - Another advantage is that the new code makes it much easier to build
>>   your own tarballs, for example to test them before pushing to code.
>>   You can just do `make build/[PKGNAME]` and the resulting package will
>>   be built in `archive/[PKGNAME]-[VERSION].tar.
> That almost worked. "make build/<package>" (or `elpaa--make-one-package')
> calls `elpaa--external-package-sync', which pulls.  That of course is not
> desirable when one wants to test some other revision of the package than
> what would end up being pulled.

Could you give some detail about the situation in which doing `git pull`
was a problem for you?

I mean, obviously I could just move that call to
`elpaa--external-package-sync` elsewhere, but `elpaa--make-one-package'
is supposed to make packages from *commits* (it normally makes two
packages, one from the head of the branch and another from the last
commit that changed `Version:` line) so it "inherently" moves between
different commits.


        Stefan