Tag: Firefox

`xdg-open` fails when using Firefox under Wayland

Recently I noticed xdg-open started failing opening links in Firefox. Giving me the following error:

Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.

Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.

It happened while I had Firefox running and responding to everything else. I’m running the latest stable Firefox (74 as I’m writing this) on Wayland. Wayland brings a lot of good things, but also a lot of interoperability problems, so I suspected it had something to do with it. Thanks to Martin Stransky I found out that the solution is to set the MOZ_DBUS_REMOTE environment variable prior to launching Firefox. If you are using a desktop file to launch Firefox, you can set the variable in the Exec line like this:

[Desktop Entry]
Type=Application
Name=Firefox
Exec=env MOZ_DBUS_REMOTE=1 MOZ_ENABLE_WAYLAND=1 /home/guyru/.local/firefox/firefox %u
X-MultipleArgs=false
Icon=firefox-esr
Categories=Network;WebBrowser;
Terminal=false
MimeType=text/html;text/xml;application/xhtml+xml;application/xml;application/vnd.mozilla.xul+xml;application/rss+xml;application/rdf+xml;image/gif;image/jpeg;image/png;x-scheme-handler/http;x-scheme-handler/https;

You will need to restart Firefox before the fix will take affect.

Yubikey doesn’t work on Firefox installed via Snap

Installing Firefox via Snap is an easy way to get the latest Firefox version on your favorite distro, regardless of the version the distro ships with. However, due to Snap’s security model, Yubikeys, or any other FIDO tokens do not work out of the box. To enable U2F devices, like Yubikeys, you need to give the Firefox package the necessary permissions manually:

$ snap connect firefox:u2f-devices

Installing Firefox Quantum on Debian Stretch

Debian only provides the ESR (Extended Support Release) line of Firefox. As a result, currently, the latest version of Firefox available for Debian Stretch is Firefox 52, which is pretty old. Lately, Firefox 57, also known as Quantum, was released as Beta. It provides many improvements over older Firefox releases, including both security and performance.

Begin by downloading the latest beta (for Firefox 57) and extract it to your home directory:


$ wget -O firefox-beta.tar.bz2 "https://download.mozilla.org/?product=firefox-beta-latest&os=linux64&lang=en-US"
$ tar -C ~/.local/ -xvf firefox-beta.tar.bz2

This installs Firefox to your current user. Because Firefox is installed in a user-specific location (and without root-priveleges), Firefox will also auto-update when new versions are released.

If you prefer using the stable version of firefox, simply replace the first step by


$ wget -O firefox-stable.tar.bz2 "https://download.mozilla.org/?product=firefox-latest&os=linux64&lang=en-US"

Next, we take care of desktop integration. Put the following in ~/.local/share/applications/firefox-beta.desktop:


[Desktop Entry]
Type=Application
Name=Firefox Beta
Exec=/home/guyru/.local/firefox/firefox %u
X-MultipleArgs=false
Icon=firefox-esr
Categories=Network;WebBrowser;
Terminal=false
MimeType=text/html;text/xml;application/xhtml+xml;application/xml;application/vnd.mozilla.xul+xml;application/rss+xml;application/rdf+xml;image/gif;image/jpeg;image/png;x-scheme-handler/http;x-scheme-handler/https;

Building CookieJar out of Firefox’s cookies.sqlite

Firefox 3 started to store it’s cookies in a SQLite database instead of the old plain-text cookie.txt. While Python’s cookielib module could read the old cookie.txt file, it doesn’t handle the new format. The following python snippet takes a CookieJar object and the path to Firefox cookies.sqlite (or a copy of it) and fills the CookieJar with the cookies from cookies.sqlite.

import sqlite3
import cookielib

def get_cookies(cj, ff_cookies):
    con = sqlite3.connect(ff_cookies)
    cur = con.cursor()
    cur.execute("SELECT host, path, isSecure, expiry, name, value FROM moz_cookies")
    for item in cur.fetchall():
        c = cookielib.Cookie(0, item[4], item[5],
            None, False,
            item[0], item[0].startswith('.'), item[0].startswith('.'),
            item[1], False,
            item[2],
            item[3], item[3]=="",
            None, None, {})
        print c
        cj.set_cookie(c)

It works well for me, except that apperantly Firefox doesn’t save session cookies to the disk at all.