package-build-*-function: Remove experimental variables

This was useful during development and I considered sharing clones
between Melpa and the Emacsmirror locally.  The former has run its
course and the latter is not feasible because package-build.el
happily deletes clones, which would severely mess with emir.el.

These variables were always marked as experimental and users were
told to inform me if these were of use to them.

package-build.el

@@ -180,15 +180,6 @@ packages are distributed without using tarballs."
                  (const :tag "only use tarball for multi-file packages" nil)
                  function))
 
-;; NOTE that these hooks are still experimental.  Let me know if these
-;; are potentially useful for you and whether any changes are required
-;; to make them more appropriate for your usecase.
-(defvar package-build-worktree-function #'package-recipe--working-tree)
-(defvar package-build-early-worktree-function #'package-recipe--working-tree)
-(defvar package-build-fetch-function #'package-build--fetch)
-(defvar package-build-checkout-function #'package-build--checkout)
-(defvar package-build-cleanup-function #'package-build--cleanup)
-
 (defcustom package-build-run-recipe-org-exports nil
   "Whether to export the files listed in the `:org-exports' recipe slot.
 Note that Melpa leaves this disabled."
@@ -300,7 +291,9 @@ enabled by default, to avoid accidentially not using it.")
     "--tmpfs" "/tmp"))
 
 (defvar package-build--inhibit-fetch nil
-  "Whether to inhibit fetching.  Useful for testing purposes.")
+  "Whether to inhibit fetching.  Useful for testing purposes.
+If `strict', also inhibit the initial clone, and deleting and
+re-cloning an existing clone after the upstream has changed.")
 
 (defvar package-build--inhibit-checkout nil
   "Whether to inhibit checkout.  Useful for testing purposes.")
@@ -347,7 +340,7 @@ being run for a particular package."
 
 (defun package-build--select-version (rcp)
   (pcase-let*
-      ((default-directory (package-build--working-tree rcp t))
+      ((default-directory (package-recipe--working-tree rcp))
        (`(,commit ,time ,version)
         (cond
          ((with-no-warnings package-build-get-version-function)
@@ -864,23 +857,17 @@ Use a sandbox if `package-build--use-sandbox' is non-nil."
   (apply #'package-build--call-process nil command args))
 (make-obsolete 'package-build--run-process 'package-build--call-process "5.0.0")
 
-;;; Worktree
-
-(defun package-build--working-tree (rcp &optional early)
-  (if early
-      (funcall package-build-early-worktree-function rcp)
-    (funcall package-build-worktree-function rcp)))
-
 ;;; Fetch
 
 (cl-defmethod package-build--fetch ((rcp package-git-recipe))
-  (let ((dir (package-build--working-tree rcp t))
+  (let ((dir (package-recipe--working-tree rcp))
         (url (package-recipe--upstream-url rcp))
         (protocol (package-recipe--upstream-protocol rcp)))
-    (unless (member protocol package-build-allowed-git-protocols)
+    (cond
+     ((eq package-build--inhibit-fetch 'strict))
+     ((not (member protocol package-build-allowed-git-protocols))
       (package-build--error rcp
         "Fetching using the %s protocol is not allowed" protocol))
-    (cond
      ((and (file-exists-p (expand-file-name ".git" dir))
            (let ((default-directory dir))
              (string= (car (process-lines "git" "config" "remote.origin.url"))
@@ -903,9 +890,10 @@ Use a sandbox if `package-build--use-sandbox' is non-nil."
         (package-build--call-process rcp "git" "clone" url dir))))))
 
 (cl-defmethod package-build--fetch ((rcp package-hg-recipe))
-  (let ((dir (package-build--working-tree rcp t))
+  (let ((dir (package-recipe--working-tree rcp))
         (url (package-recipe--upstream-url rcp)))
     (cond
+     ((eq package-build--inhibit-fetch 'strict))
      ((and (file-exists-p (expand-file-name ".hg" dir))
            (let ((default-directory dir))
              (string= (car (process-lines "hg" "paths" "default")) url)))
@@ -1328,7 +1316,7 @@ order and can have the following form:
   renamed and/or moved to DEST.  SRC and DEST are relative file
   names (as opposed to globs) and both may contain directory
   parts.  SRC must exist.  Avoid using this, if at all possible."
-  (let ((default-directory (or repo (package-build--working-tree rcp)))
+  (let ((default-directory (or repo (package-recipe--working-tree rcp)))
         (spec (or spec (oref rcp files)))
         (name (oref rcp name)))
     (when (eq (car spec) :defaults)
@@ -1468,7 +1456,7 @@ are subsequently dumped."
            (message "Package: %s" name)
            (message "Fetcher: %s" fetcher)
            (message "Source:  %s\n" url)))
-    (funcall package-build-fetch-function rcp)
+    (package-build--fetch rcp)
     (unless package-build--inhibit-build
       (package-build--select-version rcp)
       (setq version (oref rcp version))
@@ -1498,10 +1486,10 @@ are subsequently dumped."
   "Build the package version specified by RCP.
 Return the archive entry for the package and store the package
 in `package-build-archive-dir'."
-  (let ((default-directory (package-build--working-tree rcp)))
+  (let ((default-directory (package-recipe--working-tree rcp)))
     (unwind-protect
         (progn
-          (funcall package-build-checkout-function rcp)
+          (package-build--checkout rcp)
           (when-let* ((package-build-run-recipe-shell-command)
                       (command (oref rcp shell-command)))
             (package-build--message "Running %s" command)
@@ -1525,7 +1513,7 @@ in `package-build-archive-dir'."
             (when package-build-badge-data
               (package-build--write-badge-image
                (oref rcp name) (oref rcp version) package-build-archive-dir))))
-      (funcall package-build-cleanup-function rcp))))
+      (package-build--cleanup rcp))))
 
 (defun package-build--build-single-file-package (rcp files)
   (pcase-let* (((eieio name version commit) rcp)

test/package-build-tests.el

@@ -26,8 +26,8 @@
 (defmacro package-build-test-package (&rest body)
   (declare (indent 0) (debug t))
   `(let* ((package-build-verbose nil)
-          (package-build-fetch-function #'ignore)
-          (package-build-checkout-function #'ignore)
+          (package-build--inhibit-fetch 'strict)
+          (package-build--inhibit-checkout t)
           (package-build-stable nil)
           (package-build-snapshot-version-functions
            (list #'package-build-release+count-version))