[Support]: Unable to determine elpaca-core-date

[Icy-Thought]

Elpaca Version

Elpaca f752db6 HEAD -> master, origin/master, origin/HEAD
installer: 0.6
emacs-version: GNU Emacs 30.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.38, cairo version 1.18.0)
git --version: git version 2.42.0

Operating System

Linux 6.6.8, NixOS, 24.05 (Uakari), 24.05.20231222.6df37dc

Description

Debugger entered--Lisp error: (wrong-type-argument number-or-marker-p ((emacs "Unable to determine elpaca--core-date" nil nil)))
  version-list-<((((emacs "Unable to determine elpaca--core-date" nil nil))) (20231204))

Emacs is unable to load my config properly because of git-commit inability to be updated (elpaca--core-date), which is caused by my use of Emacs built from the master branch. And I think the cause for this issue lies within elpaca.el lack of support for master branch versions of Emacs.

elpaca/elpaca.el

Lines 1106 to 1111 in f752db6

	(defvar elpaca--core-date
	(list (or (and emacs-build-time (string-to-number (format-time-string "%Y%m%d" emacs-build-time)))
	(alist-get emacs-version '(("27.1" . 20200804) ("27.2" . 20210319) ("28.1" . 20220403)
	("28.2" . 20220912) ("29.1" . 20230730))
	nil nil #'equal)
	(warn "Unable to determine elpaca--core-date"))))

Therefore I thought I should ask if there is a plan to support master branch versions of Emacs or not

[progfolio]

[Is there] a plan to support [Emacs] master branch?

Yes. I use the master branch myself.

I recently added dependency version constraint checks to Elpaca: 85bfd98

The core date is a YYYYMMDD format version for all of the bundled, or core, elisp shipped with Emacs.
Elpaca is able to figure this out for stable releases and uses emacs-build-time when it is available (for people actively developing core packages). When users are not on a stable release and emacs-build-time is not set, the variable will need to be manually set.

The reason this variable is needed in the first place is an unfortunate side effect of the current state of elisp versioning. Rather than agree on a single versioning scheme, several incompatible schemes have developed over time. MELPA versions packages with a YYYYMMDD date-based format, and a handful of packages (git-commit in your case) declare minimum required dependency versions in that style.
The core date is a "best guess" way of dealing with this inconsistency.

Debugger entered--Lisp error: (wrong-type-argument number-or-marker-p ((emacs "Unable to determine elpaca--core-date" nil nil)))
  version-list-<((((emacs "Unable to determine elpaca--core-date" nil nil))) (20231204))

This should be taken care of via 5657f92.
A warning will be displayed when it is unable to be determined automatically.
In those cases the elpaca-core-date variable should be set prior to packages being queued.
e.g.

(setq elpaca-core-date '(20231228)) ;; set to the build date of Emacs

That date will be used when a package depends on a built-in package, requesting a minimum version in MELPA version date-based schema.

Does that help?

[Icy-Thought]

Rather than agree on a single versioning scheme, several incompatible schemes have developed over time.

Oh, that is rather unfortunate.

Does that help?

Yes it does! Thank you for taking the time to explain the situation to me! I'll add (setq elpaca-core-date "YYYYMMDD") to my Emacs setup.

[progfolio]

Glad to hear it. Thanks for taking the time to fill out a ticket.

[progfolio]

Just for curiosity's sake, what is the value of the source-directory variable on your version of Emacs? I expect to be nil, but if it's non-nil, I may be able to automate the elpaca-core-date variable in your case.

[Icy-Thought]

C-h v source-directory returns Its value is "/build/source/".

[Icy-Thought]

Also, adding (setq elpaca-core-date "20231211") prior to elpaca-wait in my bootstrap process yields elpaca--check-version: (wrong-type-argument listp "20231211").

Code:

;; <-- bootstrap code provided in the readme -->

;; Applying minor configurations to our new package manager
(unless (fboundp 'use-package)
  (elpaca use-package (require 'use-package)))

(elpaca elpaca-use-package
  (elpaca-use-package-mode)
  (setq elpaca-use-package-by-default t
           elpaca-core-date "20231211"))

;; Verify code evaluation before proceeding
(elpaca-wait)

[progfolio]

adding (setq elpaca-core-date "20231211") prior to elpaca-wait in my bootstrap process yields elpaca--check-version: (wrong-type-argument listp "20231211")

Apologies, it should be (setq elpaca-core-date '(20231211)).

C-h v source-directory returns Its value is "/build/source/".

I'm not familiar with NixOS. Does the following return non-nil?:

(when-let (((file-exists-p source-directory))
           (default-directory source-directory))
  (elpaca-process-call "git" "log" "-n" "1" "--format=%cd" "--date=format:%Y%m%d.%s"))

[Icy-Thought]

Evaluating that function by copy-pasting returns nothing, but when I supply the elpaca-process-call to eval-expression for the last line only I get (0 "20231228.1703776929" nil)

[progfolio]

It would need to be non-nil for the whole expression.
Unfortunately, it doesn't look like that method will work with NixOS.
Manually setting elpaca-core-date will have to do for now. Thanks for testing.