As part of my production upgrade to 30.1, and before I wrote a program to install my local ELPA tree from scratch, I tried to first curate my packages and change from MELPA to generally equivalent GNU ELPA or non-GNU ELPA archives.  The result was that I had two of each package installed.

I think there's a bug in 'package-install' which, when invoked from 'package-install-button-action', processes the new package spec, and incorrectly checks to see if the package is already installed.  Interactive invocation of 'package-install' yields the package name from the prompt, not its archive description.

If the below is correct, I can submit a patch to make 'package-install' behave like 'package-reinstall' for the non-interactive case.

(defun package-install (pkg &optional dont-select)

...

    (if-let* ((transaction
               (if (package-desc-p pkg)

;; Problem seems to be here.  If the new pkg desc is for a 

;; different archive directory name style, package-installed-p

;; fails as it checks to see if the new directory exists (which

;; does not), ignoring the old archive directory.
                   (unless (package-installed-p pkg)
                     (package-compute-transaction (list pkg)
                                                  (package-desc-reqs pkg)))