Dear Eli,

I did not get any input on the *Backtrace* buffer after I entered M-x debug-on-entry RET handle-switch-frame RET

Please find the output from emacs --debug-init:
********* output from emacs --debug-init**************
Debugger entered--Lisp error: (file-missing "Cannot open load file" "No such file or directory" "e2wm")
  require(e2wm)
  eval-buffer(#<buffer  *load*> nil "/home/partha/.emacs" nil t)  ; Reading at buffer position 697
  load-with-code-conversion("/home/partha/.emacs" "/home/partha/.emacs" t t)
  load("~/.emacs" t t)
  #f(compiled-function () #<bytecode 0x255119>)()
  command-line()
  normal-top-level()
*******************************************************************

With all the very best wishes and regards,

partha

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পার্থ প্রতিম ঘোষ

[cid:1c75408b-925b-44ac-81a4-173726b843f1]
________________________________
থেকে: Eli Zaretskii <eliz@gnu.org>-এর পক্ষ থেকে help-gnu-emacs <help-gnu-emacs-bounces+ghoshpp=unisa.ac.za@gnu.org>
পাঠান: 24 মার্চ 2019 20.51
প্রতি: help-gnu-emacs@gnu.org
বিষয়: Re: get backtrace of handle-switch-frame

> From: Amos Bird <amosbird@gmail.com>
> Date: Mon, 25 Mar 2019 02:21:32 +0800
>
> Hello, is it possble to get the backtrace of function
> `handle-switch-frame` so that I can find out the cause of an
> unexpected frame switch event?

I think you should be able to use debug-on-entry for that purpose.