Re: Where does MELPA's package versions come from?

[Jean Louis]

* Stefan Monnier <monnier@iro.umontreal.ca> [2020-11-13 07:36]:
> E.g. at https://stable.melpa.org/#/camlhttps://github.com/ocaml/caml-mode
> 
> I see that the package is released as version 4.7.1 but I can't figure
> out where this info comes from: the recipe is
> 
>     (caml :repo "ocaml/caml-mode" :fetcher github)
> 
> and the code at https://github.com/ocaml/caml-mode doesn't seem to say
> "4.7.1" anywhere either.
> 
> So where does MELPA find the release version number?

MELPA does not acknowledge author's version number or convention on
packaging.

It is trying to cope with wrongly written version numbers and uses
probably the date when package was last time fetched from archive. For
example this commithere is from 2nd July 2019 and MELPA injected
automatically package version of 3rd July 2019.

;; Author: Elis "etu" Axelsson
;; URL: https://github.com/etu/0blayout
;; Package-Commit: fd9a8f353dbd45b4628b5f84b8d8c2525ebf571d
;; Package-Version: 20190703.527
;; Package-X-Original-Version: 20160918.0
;; Version: 1.0.2
;; Keywords: convenience, window-management

>From MELPA's script package-build.el:

      (with-current-buffer (find-file pkg-target)
        (package-build--update-or-insert-header "Package-Commit" commit)
        (package-build--update-or-insert-header "Package-Version" version)
        (package-build--ensure-ends-here-line pkg-source)
        (write-file pkg-target nil)