Creating a pull request with H p signals error (wrong-type-argument stringp nil)

[treese]

I tried to create a pull request, and got a Lisp error (backtrace details below). It's entirely possible that I did something wrong. I did the following:

• magithub-clone to clone my fork of someone else's repository on GitHub
• made a feature branch (update-8-30)
• edit/commit/push my feature branch to my fork repop
• H p to make a pull request

It prompts for a head branch, which I think is supposed to be my feature branch (update-8-30). After I hit return for that, I get the following stack backtrace:

Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  regexp-quote(nil)
  (concat (regexp-quote remote) "/\\(.*\\)")
  (let ((regexp (concat (regexp-quote remote) "/\\(.*\\)"))) (mapcar (function (lambda (it) (and (string-match regexp it) (match-string 1 it)))) (magit-list-remote-branch-names remote)))
  magithub-remote-branches(nil)
  (let ((branches (magithub-remote-branches remote))) (magit-completing-read (format "[%s] %s" (magithub-repo-name (magithub-repo-from-remote remote)) prompt) branches nil t nil nil (and (member default branches) default)))
  magithub-remote-branches-choose("Base branch" nil "master")
  (let* ((this-repo (magithub-read-repo "Fork's remote (this is you!) " (ghubp-username) t)) (this-repo-owner (let ((alist this-repo)) (let ((\.owner\.login (cdr ...))) \.owner\.login))) (parent-repo (or (alist-get (quote parent) this-repo) this-repo)) (this-remote (car (magithub-repo-remotes-for-repo this-repo))) (on-this-remote (string= (magit-get-push-remote) this-remote)) (base-remote (car (magithub-repo-remotes-for-repo parent-repo))) (head-branch (let ((branch (magithub-remote-branches-choose "Head branch" this-remote (if on-this-remote ...)))) (if (magit-rev-verify (magit-get-push-branch branch)) nil (user-error "`%s' has not yet been pushed to your fork (%s)" branch (magithub-repo-name this-repo))) branch)) (base (magithub-remote-branches-choose "Base branch" base-remote (or (and on-this-remote (magit-get-upstream-branch head-branch)) (let ((alist parent-repo)) (let (...) \.default_branch))))) (user+head (format "%s:%s" this-repo-owner head-branch))) (if (let ((G266 (ghubp-get-context)) ghubp-contextualize-function) (setq G266 (cons (cons (quote auth) (quote magithub)) G266)) (setq ghubp-contextualize-function (function (lambda nil G266))) (ghubp-get-repos-owner-repo-pulls parent-repo nil :head user+head)) (progn (user-error "A pull request on %s already exists for head \"%s\"" (magithub-repo-name parent-repo) user+head))) (list (cons (quote repo) parent-repo) (cons (quote base) base) (cons (quote head) (if (string= this-remote base-remote) head-branch user+head)) (cons (quote head-no-user) head-branch) (cons (quote fork) this-repo) (cons (quote user+head) user+head)))
  magithub-pull-request-new-arguments()
  (let ((alist (magithub-pull-request-new-arguments))) (let ((\.user+head (cdr (assq (quote user+head) alist))) (\.repo (cdr (assq (quote repo) alist))) (\.base (cdr (assq (quote base) alist))) (\.head (cdr (assq (quote head) alist))) (\.head-no-user (cdr (assq (quote head-no-user) alist)))) (magithub-confirm (quote pre-submit-pr) \.user+head (magithub-repo-name \.repo) \.base) (list \.repo \.base \.head \.head-no-user)))
  call-interactively(magithub-pull-request-new)
  magit-invoke-popup-action(112)
  funcall-interactively(magit-invoke-popup-action 112)
  call-interactively(magit-invoke-popup-action nil nil)
  command-execute(magit-invoke-popup-action)

Version information:
magithub.el says version 0.17; it's the latest (as of 8/30/18) from MELPA.
Magit version: Magit 20180828.1055, Git 2.15.2 (Apple Git-101.1), Emacs 25.3.50.1, darwin
This is Aquamacs 3.4 on Mac OS 10.13.6

Thanks for any help. It's pretty awesome to use.

[vspinu]

I am actually getting Wrong type argument: listp, magithub-issue-view-headers-hook on H p. Which comes from magithub-issue-view-insert-headers which calls magit-insert-headers which breaks.