fish-shell/fish-shell — pull request #1132 by d10n (2013-11-19 19:56:57+00:00)
Title: Do not open CLI browsers when using fish_config.

From the Python webbrowser documentation:
"If text-mode browsers are used, the calling process will block until the user exits the browser."

Running fish_config on an ssh server with no GUI browser will open a CLI browser which blocks and stops the server from handling requests.
Using multiprocess to run the server in the background lets CLI browsers access the page, but the page is unusable.

For now, disable CLI browsers and recommend opening the page in a graphical browser.
In the future, maybe write a CLI utility to change prompts and delete history items.