[ELPA] Wrong dependency headers for Ement v0.4

[Adam Porter]

Hi Stefan, et al,

I've encountered a strange situation: I recently published v0.4 of 
Ement.  The describe-package command now shows this:

  Package ement is incompatible.

     Status: Incompatible because it depends on uninstallable packages.
    Archive: gnu
    Version: 0.4
     Commit: b06c78d1ba700857330520bc796c5a29018b7ec5
    Summary: Matrix client
   Requires: emacs-27.1, map-2.1, plz-0.2, taxy-0.12.1 (not available),
               taxy-magit-section-0.9, svg-lib-0.2.5, transient-0.3.7
    Website: https://github.com/alphapapa/ement.el

However, these package headers do not match those in the listed commit, 
i.e. 
https://github.com/alphapapa/ement.el/blob/b06c78d1ba700857330520bc796c5a29018b7ec5/ement.el 
shows:

  ;; Package-Requires: ((emacs "27.1") (map "2.1") (plz "0.2") (taxy 
"0.9") (taxy-magit-section "0.9") (svg-lib "0.2.5") (transient "0.3.7"))

The package headers listed on ELPA correspond to a different commit I 
added later, which had that mistake in it 
(https://github.com/alphapapa/ement.el/commit/529c6b21e7e2c18d2dbcf35359829c3a907a41bc), 
which I've since corrected on git master 
(https://github.com/alphapapa/ement.el/commit/81caaae8fd33b67759bbd7403e3e98143acb2915).

I'd like to push a v0.4.1, just hoping that it would trigger ELPA to use 
the correct dependency headers, but I've since pushed a v0.5-pre version 
to git master, in which I'm preparing the next stable release, so I 
can't make a v0.4.1 release for ELPA, since it reads from the same branch.

I could go ahead and release v0.5, but I was planning to work on it 
more, to fix some bugs that I didn't want to release yet.  So I'm not 
sure what to do now.

Aside: This is one way in which MELPA is a bit easier to work with: 
although MELPA Stable is generally not recommended for use (due to 
various issues), it builds packages from version tags rather than git 
master (regular MELPA builds from git master); if ELPA worked the same 
way, I could easily tag a v0.4.1 independently of what's on the master 
branch.

Given that, would it be possible to have ELPA build from a separate 
branch?  That's how I organize some of my other packages, with a 
"stable" branch and a master branch.  If ELPA pulled from a "stable" 
branch, I could push a fix to that while the next major version is still 
in development.

Thanks for your help.

Adam