[gkbrk]

He doesn't want a completely new browser instance, he wants Firefox to open another window but depending on its mood Firefox refuses to do this.

Chrome can do this just fine btw.

Running Firefox from the command line isn't an obscure thing either, clicking a link on other apps like Signal or Telegram also use this method to spawn new tabs/windows. And depending on how you executed the first instance, you run into problems with clicking links on other apps as well.

I pretty much need to open Firefox first before clicking links on other apps, because otherwise I can't run Firefox normally later without killing the process.

[k8svet]

No. Sorry. I have a list of complaints with Firefox but this is clearly user error. I do this literally every day for a decade or more. It works fine. It particularly helps to not unnecessarily use things that can affect the env like launching a browser with su. In fact I can I think it a list of things that could go wrong with that.

[gkbrk]

Yes, sorry. This is a Firefox bug and not user error.

On my Linux system, this works with any other browser I try. It only fails with Firefox. If this is user error, it seems every other browser handles user errors much better.

- Firefox: First window is open, running `firefox URL` from the other terminal hangs for 15-20 seconds and then shows the popup "Firefox is already running, but is not responding. To use Firefox, you must first close the existing Firefox process, restart your device, or use a different profile.". No new tabs or windows are spawned.

- Chromium: First window is open, running a `chromium URL` command from the other terminal opens a new tab on the existing window.

- Microsoft Edge: First window is open, running a `microsoft-edge-stable URL` command from the other terminal opens a new tab on the existing window.

- Ladybird: First window is open, running `ladybird` in the other terminal opens a new ladybird window.

- Emacs/eww: First window is open, running `emacs --eval '(eww "example.com")'` on another terminal opens a new browser window.

- Netsurf: First window is open, running `netsurf URL` from the other terminal opens a new netsurf window.

- Dillo: First window is open, running `dillo URL` from the other terminal opens a new dillo window.

- Links/XLinks: First window is open, running `xlinks -G URL` from the other terminal opens a new links window.

You can see a clear pattern. Got any other browsers that refuse to run with a message like that? Or is this not a fault of Firefox, and something super extra that everything from other mainstream browsers to more obscure ones somehow handle for the user?

[TheCapeGreek]

I have never had Firefox do this. I've used all 3 major OS types in the last 5 years and Firefox on all of them. New windows open, no muss no fuss.

>I pretty much need to open Firefox first before clicking links on other apps, because otherwise I can't run Firefox normally later without killing the process.

The only way I imagine this happening is if one doesn't save the browser session between launches, maybe? I've had "cold start" link opens and it just adds another tab to my existing pinned tabs/open tabs/etc.

Everyone has different workflows I suppose.

[JonathanBeuys]

Exactly.

It seems to be some magic Firefox puts somewhere (In the environment?) that prevents it to launch a new window from a fresh terminal that is not inherited from the same parent that launched the first window.