Problem contacting Firefox from Emacs daemon started as systemd service

Problem contacting Firefox from Emacs daemon started as systemd service

[Sébastien Gendre]

Hello.

I start an Emacs daemon at the start of my session with a systemd (user)
service. When I try to open an URL from Emacs, I got this error message
from Firefox:

Firefox is already running, but is not responding. The old Firefox
process must be closed to open a new window.

But if I call this command from a simple terminal:
firefox https://fsf.org

In Firefox, a new tab open on the FSF website, with no problem.

`browse-url-browser-function` value is `browse-url-default-browser`. That
mean Emacs call xdg-open, who call firefox command.


Have you an idea about this problem ? I can't found anything on the web.

Re: Problem contacting Firefox from Emacs daemon started as systemd service

[Eli Zaretskii]

> From: Sébastien Gendre <seb@k-7.ch>
> Date: Thu, 21 Jan 2021 20:14:59 +0100
> 
> I start an Emacs daemon at the start of my session with a systemd (user)
> service. When I try to open an URL from Emacs, I got this error message
> from Firefox:
> 
> Firefox is already running, but is not responding. The old Firefox
> process must be closed to open a new window.
> 
> But if I call this command from a simple terminal:
> firefox https://fsf.org
> 
> In Firefox, a new tab open on the FSF website, with no problem.
> 
> `browse-url-browser-function` value is `browse-url-default-browser`. That
> mean Emacs call xdg-open, who call firefox command.
> 
> 
> Have you an idea about this problem ? I can't found anything on the web.

The 'firefox' command line asks the existing instance of Firefox to
display the URL, whereas xdg-open tries to start a new instance.

Re: Problem contacting Firefox from Emacs daemon started as systemd service

[Sébastien Gendre]

Thanks for your reply.

If I run the Firefox command from a shell in Emacs, I got the same
problem as when I try to open an url from Emacs.


Eli Zaretskii writes:

>> From: Sébastien Gendre <seb@k-7.ch>
>> Date: Thu, 21 Jan 2021 20:14:59 +0100
>> 
>> I start an Emacs daemon at the start of my session with a systemd (user)
>> service. When I try to open an URL from Emacs, I got this error message
>> from Firefox:
>> 
>> Firefox is already running, but is not responding. The old Firefox
>> process must be closed to open a new window.
>> 
>> But if I call this command from a simple terminal:
>> firefox https://fsf.org
>> 
>> In Firefox, a new tab open on the FSF website, with no problem.
>> 
>> `browse-url-browser-function` value is `browse-url-default-browser`. That
>> mean Emacs call xdg-open, who call firefox command.
>> 
>> 
>> Have you an idea about this problem ? I can't found anything on the web.
>
> The 'firefox' command line asks the existing instance of Firefox to
> display the URL, whereas xdg-open tries to start a new instance.

Re: Problem contacting Firefox from Emacs daemon started as systemd service

[Eli Zaretskii]

> From: Sébastien Gendre <seb@k-7.ch>
> Cc: help-gnu-emacs@gnu.org
> Date: Thu, 21 Jan 2021 21:53:32 +0100
> 
> If I run the Firefox command from a shell in Emacs, I got the same
> problem as when I try to open an url from Emacs.

Maybe some shell alias is involved?

I don't have a complete and ready solution to your problem, it's
something you will have to investigate.  I thought I'd give you the
information I do have to point you in the right direction, since you
said you don't find anything pertinent on the Internet.  The problem
here is that you need to tell Firefox to use the existing running
instance to display the new URL.  Both browse-url-browser-function
and/or browse-url-default-browser should be taught to do that.  I
suggest to try using browse-url-firefox as your first step.  If that
works, customize browse-url-browser-function to use it.  If that
doesn't work, I suggest to search the Firefox Help information for the
solution to this problem, starting from the error message you get.