Subject: bug#20015: 25.0.50; Slow Emacs startup after recent TRAMP changes

From: Tassilo Horn <[email-masked]>
Date: Fri, 06 Mar 2015 09:53:20 +0100

Michael Albinus <[email-masked]> writes:

Hi Michael,

>> Since the recent TRAMP changes on master, emacs startup takes about a
>> minute.  Starting it with
>>
>>   emacs -Q --eval "(progn (setq debug-on-quit t) (require 'tramp))"
>>
>> then waiting till it hangs and hitting C-g reveals:
>>
>> --8<---------------cut here---------------start------------->8---
>> Debugger entered--Lisp error: (quit)
>>   call-process("ssh" nil t nil "-o" "ControlPath=%C" "host.does.not.exist")
>
> What happens when you apply "ssh -o ControlPath=%C
> host.does.not.exist" locally? Same delay for one minute?

Yes, or rather it are exactly 30 seconds.

% time ssh -o ControlPath=%C host.does.not.exist
ssh: Could not resolve hostname host.does.not.exist: Name or service not known
ssh -o ControlPath=%C host.does.not.exist  0,00s user 0,00s system 0%
cpu 30,019 total

> Which ssh version do you run locally? Check with "ssh -V".

% ssh -V                           
OpenSSH_6.7p1, OpenSSL 1.0.2 22 Jan 2015

Bye,
Tassilo