Clicking on any Emacs menu calls Tramp, pauses(hangs)

[yary]

This is probably due to some library using Tramp, and not Tramp's
responsibility, but the error makes this the most convenient place to
start looking...

GNU Emacs 25.2.1 (x86_64-apple-darwin13.4.0, NS appkit-1265.21 Version
10.9.5 (Build 13F1911))
 of 2017-04-21

Clicking on any menu, eg File or Edit or Buffers or Tools, does not
open the menu, but instead shows "Tramp: Waiting for prompts from
remote shell..."

Especially annoying with this, is that ^g doesn't exit the hang. It
does stop the little spinner after the message from spinning, but it
doesn't let me resume editing.

I haven't used Tramp this session, though I did in a previous one, and
have recent files, session variables reloaded through various emacs
customizations and libraries (not sure which anymore!)

I ran tramp-cleanup-all-connections and set debug-level to 6, but I am
NOT including the debug traces here because it does not show anything
about the call stack. For this issue, I'm not interested in Tramp's
behavior/timeout- I want to find out what is trying to check a remote
file, and fix that. What's a good way to debug that? Can I have Tramp
show the stack trace when it's being called?

Setting debug-on-quit and hitting ^g opens the debugger, but
*Backtrace* shows only "Debugger entered--Lisp error: (quit)" - no
frames, no backtrace. Perhaps due to the delayed nature of ^g "quit"
with this.

Quitting emacs, running it as emacs -Q, and removing this entry from
~/.emacs.d/.session "session-file-alist" fixes my immediate problem-

("/sudo:address@hidden:/private/etc/apache2/httpd.conf" 9311 8236 1
nil nil 8236 (overwrite-mode))
("/sudo:address@hidden:/private/etc/apache2/other/mySite.conf" 505 555
1 nil nil 505 (overwrite-mode))

How can I make sure that tramp entries like the above in
"session-file-alist" don't cause problems- or where's a better place
to ask?

Thanks, in advance!

-y