Switching Browser

Posted on by Chris Warburton

I've been a big fan of the Conkeror Web browser for many years, using it as my "main" browser (opening occasional sites in Firefox, Chromium, Dillo, w3m, etc. if the mood takes me); however, this has become less tenable recently, so I've finally decided to bite the bullet and switch away. Here I'll document my reasoning and the alternative setups I've tried.


Conkeror is an alternative GUI for Firefox, replacing the "chrome" (menu bars, etc.) with a minimalist, commandline-based, keyboard-driven UI, mostly following Emacs conventions. It also has nice features like Javascript extensibility, "web jumps" (commandline hooks into search engines, with suggestions) and a nice keyboard-driven link/image following/copying UI.

Conkeror was originally written using XUL, but that was dropped by Mozilla as a 'standalone' toolkit, so Conkeror changed to use the Firefox binary itself. More recently, as part of their "Project Quantum", Mozilla have dropped support for many old APIs that Conkeror relied on (I've got nothing against Mozilla for doing this BTW; Conkeror is just one of those niche projects that suffered as a result). For a while I stuck to the last supported version of Firefox (52), which works but is a very bad idea when it comes to security (I'm happy to use unmaintained software locally, but browsers are far too exposed to remote attackers for this to be tenable). I knew I needed to switch to something else, but would like as little disruption to my workflows and muscle-memory as possible.

Alternative Browsers

I want my "main" browser to support a decent amount of "modern" Web features: especially Javascript, but possibly also video (or else have good integration with a proper external player). Unfortunately, the spectrum of browser features is pretty polarised: the "big" engines (Firefox/Gecko and WebKit/Blink) support basically everything (including crap I'd rather avoid, like DRM and microphone access (my laptop thankfully doesn't have a camera)); all other browsers (Dillo, Netsurf, Konqueror/KHTML) support effectively no Javascript in my experience.

Hence I'm best off using one of the "big" browsers: Firefox, Chromium, Midori, etc. As you might be able to tell from my FOSS zealotry, I consider the ethics of software to be far more important than any particular functionality, so my choice is mostly going to be ideological. I find Chromium's ties to Google distasteful; this extends a little to WebKit browsers by association, but am otherwise mostly neutral about them. I consider Mozilla and Firefox to be (overall) a positive influence on the world, so I'd rather stick with them. I also use Firefox semi-frequently, and appreciate things like NoScript and uBlockOrigin; it also uses GTK properly, since it handles dark themes without issue, which Chromium seems to fail at.

Staying Up To Date

The only reason I'm ditching Conkeror is that I want to use a maintained, up-to-date browser for security reasons; however, packages from official Linux distro repositories can often be out of date. Also, I use NixOS, which tends to build from source with a cache of pre-built binaries; those caches have been dropped for i686 users recently, and I'd rather avoid repeatedly building something as hefty as Firefox from source.

To solve both of these issues I've created a Nix package out of the latest binary release of Firefox from Mozilla, which I've written below. Some notes:

with builtins;
with import <nixpkgs> {};
with lib;
with rec {
  # Update these as needed
  version = "70.0.1";
  sha256  = "06xzb22qa2l04nw6992y648isnhdscpx3v75ba2vqw2b07ghfcam";

  # Fetches latest version number from mozilla.org
  latest = import (runCommand "latest-firefox-version.nix"
      __noChroot    = true;
      buildInputs   = [ wget ];
      cacheBuster   = toString currentTime;
      url           = https://www.mozilla.org/en-US/firefox/releases;
      SSL_CERT_FILE = "${cacert}/etc/ssl/certs/ca-bundle.crt";
      wget -O- "$url" | grep -o 'data-latest-firefox="[^"]*"' |
                        grep -o '".*"' > "$out"

  # Warn if version isn't the latest. onlineCheck comes from my Nix config; an
  # env var lets us skip these checks (e.g. if we're offline)
  warn = if onlineCheck && compareVersions version latest == -1
            then trace (toJSON {
                   inherit latest version;
                   WARNING = "Newer Firefox is out";
            else (x: x);

  url = warn concatStrings [

  # unpack comes from my Nix config; it extracts the output of a derivation.
  contents = unpack (fetchurl { inherit sha256 url; });

  # This script will run in the chroot, launching Firefox with needed env vars.
  # mkBin comes from my Nix config: it writes 'script' to a file in bin/ and
  # uses 'makeWrapper' to add 'paths' to PATH and 'vars' to the environment,
  raw = mkBin {
    name   = "firefoxWrapper";
    paths  = [ bash fail ];
    vars   = {
      inherit contents;

      # Avoid "Locale not supported by C library"
      LANG   = "C";
      LOCALE = "C";

      # Avoid Fontconfig error: Cannot load default config file
      FONTCONFIG_FILE = makeFontsConf {
        fontDirectories = [];
    script = ''
      #!/usr/bin/env bash
      set -e

      # Make gsettings schemas available, to avoid file dialogues crashing
      function addSchemas {
        for D in "$1"*
          export XDG_DATA_DIRS="$D:$XDG_DATA_DIRS"
        [[ "$FOUND" -eq 1 ]] || fail "No schemas found for '$1'"
      addSchemas "${gsettings-desktop-schemas.out}/share/gsettings-schemas/gsettings-desktop-schemas-"
      addSchemas "${gtk3.out}/share/gsettings-schemas/gtk"

      # Make GTK icons, etc. available
      export XDG_DATA_DIRS="${concatStringsSep ":" [

      exec "$contents/firefox" "$@"
buildFHSUserEnv {
  name       = "firefox";
  targetPkgs = pkgs: [ raw ] ++ (with pkgs; with xorg; [
    # These are copypasta from the nixpkgs firefox dependencies
    (lib.getDev libpulseaudio)

    # Required for glib schemas; without this, file dialogue boxen will crash

    # Avoid 'The 'hicolor' theme was not found'
  runScript = "firefoxWrapper";  # Corresponds to the 'name' of 'raw'

Recreating My Conkeror Workflow

I'm not too attached to my current habits; but likewise I see no reason to adopt the "default" way of doing things if there's a not-too-hacky alternative that suits me better.

Keyboard Navigation

Conkeror's nice link-following method is to press a key (e.g. f to follow a link, c to copy a link's URL, i to select an image, etc.) which switches to a new mode, where each link/frame/image/etc. is labelled with a number. Typing in that number chooses that object.

An Firefox extension which provides similar functionality (although using letter sequences rather than numbers) is Saka key.

This extension also makes it easy to associate custom keybindings to various browser actions, e.g. [ and ] to switch tabs instead of the clunkier Ctrl-Tab, etc. This has allowed me to recreate some of the bindings that are in my muscle-memory, like q to close the current tab. The preferences UI handily points out when bindings conflict; this is usually easy to resolve, since there's lots of functionality I have no problems disabling.

One annoyance to note is that some Web pages will hijack key presses; sometimes taking complete control of the keyboard and suppressing key press events that we'd like the browser to receive. I don't know of a general solution to this: it also happens in Conkeror, where Alt-x can always bring up a commandline which we can use to close the offending tab; I think my best bet in Firefox is using NoScript to turn off such page's Javascript.

UI Chrome

I don't want Firefox's toolbars, location bar, etc. cluttering up the screen all the time (even my Xmonad "window decorations" are only 1 pixel wide!). In more recent versions the menu bar will auto-hide (press Alt to show it), but I'd also like to hide the rest.

Thankfully this can be done by styling Firefox's "chrome" with CSS, via the chrome/userChrome.css file in Firefox's profile directory. Doing a little digging (on StackOverflow, Mozilla's support site and Reddit), I came up with the following userChrome.css code which:

/* Always hide the tab bar */
#TabsToolbar { visibility: collapse; }

/* Hide address bar and surrounding buttons unless anything inside is focused */
#nav-bar:not(:focus-within), #nav-bar:not(:focus-within) * {
        border : none !important;
        margin : 0    !important;
    max-height : 0    !important;
    min-height : 0    !important;
       padding : 0    !important;

Using visibility: collapse; or display: none; on the #nav-bar seems to permanently hide it, hence the use of border, margin, etc.

The nice thing about using not(:focus-within) on the whole #nav-bar, rather than just the focus of the address bar, is that things will remain visible when using context menus (e.g. from the built-in "burger menu", or from extensions like NoScript), even though they take focus away from the address bar.


One annoyance with Conkeror is that it has no bookmark manager. It stores bookmarks in the same way as Firefox (in an SQLite database called places), but provides no UI to manage them. I ended up using sqlitebrowser to do so.

Firefox, of course, has a very nice bookmark manager. I copied each one across manually, from SQLiteBrowser to Firefox's UI.


I've been using Firefox in "permanent private browsing" mode, which is better from a security and tracking perspective, but inconvenient for sites that require logging in.

As far as I see it, there are three setups I could use:

I was using the first with Conkeror and the last with Firefox. Now that I'm using Firefox full-time, I'd like to keep the benefits of browsing without permanent cookies, but make life more convenient by opting for the middle setup.

I already used a password manager, KeePassX, which means that:

KeePassX is actually unmaintained (it's a local, offline program; so that's OK). I was happy enough with it, but it turns out that the fork KeePassXC ("C" for "Community") is not only maintained, but it also provides a Firefox plugin too!

Getting this to work was a little tricky, since the documentation only covers the happy path ("click this and it should work!"). The error messages were rather uninformative too, and stepping through the addon's Javascript with Firefox's debugger wasn't particularly enlightening. Someone in IRC (#keepassxc on Freenode) suggested I use the latest release of KeepassXC (2.4.3) since the browser plugin might not work with older versions.

This, in turn, turned out to be rather tricky. There's currently a bug in Nixpkgs for 32bit x86 Linux which (AFAIK) causes some packages to be built with the wrong compiler (that used to "bootstrap" the system). This results in runtime crashes about unresolved names. Long story short: the qtbase package is broken from Nixpkgs 18.03 onwards.

I've been working around this by pinning Qt packages from older versions of Nixpkgs, e.g. Picard and Basket. Yet I need the newer KeePassXC packages. Thankfully Nixpkgs makes it easy to override dependencies, so I tried the following override in my Nixpkgs overlay:

keepassx-community = trace
  "FIXME: Overriding dependencies of keepassx-community to avoid broken Qt"
  super.keepassx-community.override (old: {
    inherit (self.nixpkgs1709)
    inherit (self.nixpkgs1709.qt5)
    inherit (self.nixpkgs1709.xorg)

Note that self is the whole Nixpkgs set (including my overrides) and nixpkgs1709 is my pinned copy of Nixpkgs 17.09 packages. I've added the FIXME as a reminder to myself, so if Qt ever starts working again upstream I can remove this override.

Unfortunately that wasn't enough, since the version of KeePassXC in Nixpkgs 19.03 isn't 2.4.3, it's 2.3.4. So I also ended up overriding this override (yikes!) to fiddle with its parameters. Since then version 2.5.0 has come out, which I'm using via this package (commented in-line):

In particular:

keepassx-community =
  with rec {
    # Update this as needed
    version = "2.5.0";
    src     = self.unpack (self.fetchurl {
      url    = "https://github.com/keepassxreboot/keepassxc/releases/" +
      sha256 = "10bq2934xqpjpr99wbjg2vwmi73fcq0419cb3v78n2kj5fbwwnb3";

    # Checks for the latest version number
    latest = import (self.runCommand "latest-keepassxc"
        __noChroot  = true;
        buildInputs = [ self.utillinux self.wget self.xidel ];
        nix         = self.writeScript "read-version.nix" ''
          with builtins;
          readFile ./version.txt
        pat = "//a[contains(text(),'Latest release')]/../..//a/@href";
        url = https://github.com/keepassxreboot/keepassxc/releases/latest;
        mkdir "$out"
        wget -q --no-check-certificate -O- "$url" |
          xidel - -q -e "$pat"                    |
          grep tag                                |
          rev                                     |
          cut -d / -f1                            |
          rev                                     |
          sed -e 's/^/"/g' -e 's/$/"/g' > "$out/default.nix"

    # Use known-good dependencies, to avoid broken Qt, etc.
    fixedDeps = super.keepassx-community.override (old: {
      inherit (self.nixpkgs1709)
      inherit (self.nixpkgs1709.qt5)
      inherit (self.nixpkgs1709.xorg)

    # Use newer version, for fixed and better browser integration
    updated = fixedDeps.overrideAttrs (old: rec {
      # Use the new version
      inherit src version;
      name        = "keepassxc-${version}";
      buildInputs = old.buildInputs ++ [
        self.nixpkgs1709.pkgconfig                # Needed to find qrencode
        self.qt5.qtsvg self.nixpkgs1709.qrencode  # New dependencies

      # Taken from newer Nixpkgs, avoids missing plugin error when testing
      checkPhase = ''
        export LC_ALL="en_US.UTF-8"
        export QT_QPA_PLATFORM=offscreen
        export QT_PLUGIN_PATH="${with self.nixpkgs1709.qt5.qtbase;
        make test ARGS+="-E testgui --output-on-failure"

      # Ignore the 2 patches in Nixpkgs (one Mac-only, the other upstreamed)
      patches = [];
  # Remind ourselves of this override, so we can remove it when no longer needed
  trace "FIXME: Overriding deps of keepassx-community to avoid broken Qt"
        # Emit a warning if there's a new version out; allow skipping the check
        (if self.onlineCheck && (compareVersions version latest != 0)
            then trace (toJSON {
                   inherit latest version;
                   warning = "KeePassXC version doesn't match latest";
            else (x: x))

This gives me the latest KeePassXC (which I might as well use), but it still wasn't enough to fix the browser integration! I finally figured out the problem was that the keepassxc-proxy binary wasn't running properly from the chroot environment that I'm running Firefox from.

To remedy this I wrote my own replacement:

#!/usr/bin/env python
import json
import socket
import sys
import threading
import time

# Enable this for debugging
logFile = open('/home/chris/DELETEME/keepassxc-proxy-alternative.log', 'a')
log = lambda s: None #(logFile.write(s), logFile.flush(), None)[-1]

# Talk to KeePassXC via a socket
sock           = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
server_address = '/run/user/1000/kpxc_server'
log('connecting to %s\n' % server_address)
except socket.error, msg:

def tryParse(get, so_far=""):
    """Incrementally read characters using the given 'get' function, appending
    them to the 'so_far' string. Ignore anything before the first '{', then
    parse and return one complete JSON object."""
        # Try parsing JSON from the string we've read so far
        val = json.loads(so_far)
        return val
        # If it fails, read another character
        c = ''
        while c == '':
            c = get()

        # Ignore crap at the start that's not JSON
        if so_far == "" and c != "{":
            log("Skipping char '%s'\n" % c)
            return tryParse(get, so_far)
        return tryParse(get, so_far + c)

# Communication with the KeePassXC-Browser plugin happens via stdio. Each
# message is prefixed with its length (which we handle via the 'struct' module).
import struct
def send_to_browser(message):
    sys.stdout.write(struct.pack('I', len(message)))

def read_from_browser():
    text_length_bytes = sys.stdin.read(4)

    if len(text_length_bytes) == 0:

    text_length = struct.unpack('i', text_length_bytes)[0]
    text        = sys.stdin.read(text_length).decode('utf-8')
    return text

# We have two main loops: one reads from the browser and sends to the socket
def browserToSocketMain():
        while True:
            message = read_from_browser()
            log('sending "%s"\n' % message)
    except Exception as e:
        log('Got exception: ' + repr(e))
        log('closing socket')

browserToSocketThread = threading.Thread(target=browserToSocketMain,
browserToSocketThread.daemon = True

# The second main loop reads from the socket and sends to the browser
    while True:
        response = tryParse(lambda: sock.recv(1))
        dumped   = json.dumps(response)
        log('Received: %s\n' % dumped)
except Exception as e:
    log('Got exception: ' + repr(e))
    log('closing socket')

Pointing the path entry of ~/.mozilla/native-messaging-hosts/org.keepassxc.keepassxc_browser.json to this program was enough to get the plugin talking to KeePassXC, and filling in password forms for me.

Now I can stay in private browsing mode, yet log in to sites as needed with a simple keyboard shortcut.