Introduction to Firefox

Firefox is a stand-alone browser based on the Mozilla codebase.

This package is known to build and work properly using an LFS-8.3 platform.

Package Information

Additional Downloads



Extracting the tarball will reset the permissions of the current directory to 0755 if you have permission to do that. If you do this in a directory where the sticky bit is set, such as /tmp it will end with error messages:

tar: .: Cannot utime: Operation not permitted
tar: .: Cannot change mode to rwxr-xr-t: Operation not permitted
tar: Exiting with failure status due to previous errors

This does finish with non-zero status, but it does NOT mean there is a real problem. Do not untar as the root user in a directory where the sticky bit is set - that will unset it.

As with other large packages which use C++ (or rust), the SBU times to build this vary more widely than you might expect. Also, almost 6GB of real memory is used during the final link and the SBUs can increase significantly if the machine has to swap to do this.

The mach build system (Python scripts) can be somewhat unreliable: if the build fails and reports an Error, it can still return a status of success, causing a scripted build to try to install (which does not rerun the build), fail during the preparations for installing, but still exit with a status of success. Also, on occasion it may limit itself to only running one set of jobs - that will make the build take about 3 times as long as running with four sets of jobs.

Although upstream prefer to use PulseAudio, for the moment Alsa can still be used. Both may need runtime configuration to get sound working.

Firefox Dependencies


Autoconf-2.13, Cbindgen-0.6.6, Clang (from LLVM-7.0.0), both GTK+-3.24.1 and GTK+-2.24.32, libnotify-0.7.7, NSS-3.40.1, PulseAudio-12.2 (or alsa-lib-1.1.7 if you edit the mozconfig; now deprecated by mozilla), in either case please read the Configuration Information, rustc-1.29.2, UnZip-6.0, yasm-1.3.0, and Zip-3.0




If you don't install recommended dependencies, then internal copies of those packages will be used. They might be tested to work, but they can be out of date or contain security holes.


cURL-7.62.0, dbus-glib-0.110, Doxygen-1.8.14, GConf-3.2.6, FFmpeg-4.0.2 (runtime, to play mov, mp3 or mp4 files), libwebp-1.0.1, OpenJDK-10.0.2, startup-notification-0.12, Valgrind-3.14.0, Wget-1.20, Wireless Tools-29, liboauth-1.0.3, libproxy, and (with the patch) Graphite2-1.3.12 and HarfBuzz-2.2.0

User Notes:

Installation of Firefox

The configuration of Firefox is accomplished by creating a mozconfig file containing the desired configuration options. A default mozconfig is created below. To see the entire list of available configuration options (and an abbreviated description of some of them), issue ./mach configure && ./configure --help | less. You may also wish to review the entire file and uncomment any other desired options. Create the file by issuing the following command:

cat > mozconfig << "EOF"
# If you have a multicore machine, all cores will be used by default.
# You can change the number of non-rust jobs by setting a valid number
# of cores in this option, but when rust crates are being compiled
# jobs will be scheduled for all the available CPU cores.
#mk_add_options MOZ_MAKE_FLAGS="-j1"

# If you have installed dbus-glib, comment out this line:
ac_add_options --disable-dbus

# If you have installed dbus-glib, and you have installed (or will install)
# wireless-tools, and you wish to use geolocation web services, comment out
# this line
ac_add_options --disable-necko-wifi

# API Keys for geolocation APIs - necko-wifi (above) is required for MLS
# Uncomment the following line if you wish to use Mozilla Location Service
#ac_add_options --with-mozilla-api-keyfile=$PWD/mozilla-key

# Uncomment the following line if you wish to use Google's geolocaton API
# (needed for use with saved maps with Google Maps)
#ac_add_options --with-google-api-keyfile=$PWD/google-key

# Uncomment this line if you have installed startup-notification:
#ac_add_options --enable-startup-notification

# Uncomment the following option if you have not installed PulseAudio
#ac_add_options --disable-pulseaudio
# and uncomment this if you installed alsa-lib instead of PulseAudio
#ac_add_options --enable-alsa

# If you have installed GConf, comment out this line
ac_add_options --disable-gconf

# Uncomment this if you have not installed nodejs,
# but note that nodejs will be required in firefox-64
#ac_add_options --disable-nodejs

# From firefox-61, the stylo CSS code can no-longer be disabled

# Comment out following options if you have not installed
# recommended dependencies:
ac_add_options --enable-system-sqlite
ac_add_options --with-system-libevent
ac_add_options --with-system-libvpx
ac_add_options --with-system-nspr
ac_add_options --with-system-nss
ac_add_options --with-system-icu

# The gold linker is no-longer the default
ac_add_options --enable-linker=gold

# You cannot distribute the binary if you do this
ac_add_options --enable-official-branding

# If you are going to apply the patch for system graphite
# and system harfbuzz, uncomment these lines:
#ac_add_options --with-system-graphite2
#ac_add_options --with-system-harfbuzz

# Stripping is now enabled by default.
# Uncomment these lines if you need to run a debugger:
#ac_add_options --disable-strip
#ac_add_options --disable-install-strip

# The BLFS editors recommend not changing anything below this line:
ac_add_options --prefix=/usr
ac_add_options --enable-application=browser

ac_add_options --disable-crashreporter
ac_add_options --disable-updater
# enabling the tests will use a lot more space and significantly
# increase the build time, for no obvious benefit.
ac_add_options --disable-tests

# Optimization for size is broken with gcc7 and later
ac_add_options --enable-optimize="-O2"

# From firefox-61 system cairo is not supported

ac_add_options --enable-system-ffi
ac_add_options --enable-system-pixman

# From firefox-62 --with-pthreads is not recognized

ac_add_options --with-system-bz2
ac_add_options --with-system-jpeg
ac_add_options --with-system-png
ac_add_options --with-system-zlib

mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/firefox-build-dir

Compile Firefox by issuing the following commands:

If you have installed system versions of graphite2 and harfbuzz and wish firefox to use those instead of its shipped versions, apply the patch and uncomment the appropriate entries in the mozconfig file.

patch -Np1 -i ../firefox-63.0.3-system_graphite2_harfbuzz-1.patch

If the geolocation APIs are needed:



The Google and Mozilla API Keys below are specific to LFS. If using these instructions for another distro, or if you intend to distribute binary copies of the software using these instructions, please obtain your own keys following the instructions located at and respectively.

echo "AIzaSyDxKL42zsPjbke5O8_rPVpVrLrJ8aeE9rQ" > google-key
echo "d2284a20-0505-4927-a809-7ffaf4d91e55" > mozilla-key


If you are compiling Firefox in chroot, make sure you have $SHELL environment variable set or prepend SHELL=/bin/sh. Also ensure that /dev/shm is mounted.

Fix a problem with certain versions of ICU, then invoke the Python script to compile the package.

sed -e 's/checkImpl/checkFFImpl/g' -i js/src/vm/JSContext*.h &&
export CC=clang CXX=clang++ AR=llvm-ar NM=llvm-nm RANLIB=llvm-ranlib &&
./mach build &&

The mozconfig above disables the tests because they use a lot more time and disk space for no obvious benefit. If you have nevertheless enabled them, you can run the tests by executing ./mach gtest. This will require a network connection, and to be run from within an Xorg session - there is a popup dialog when it fails to connect to ALSA (that does not create a failed test). One or two tests will fail. To see the details of the failure(s) you will need to log the output from that command so that you can review it.

Now, as the root user:

./mach install                                                  &&

mkdir -pv  /usr/lib/mozilla/plugins                             &&
ln    -sfv ../../mozilla/plugins /usr/lib/firefox/browser/

Command Explanations

sed -e 's/checkImpl/checkFFImpl/g' ...: Although the package ships with a modified version of ICU-59 and only tests that the system version, if requested, is at least 59, changes in some versions cause builds with the system version to fail with error messages of the form no void JSContext::checkImpl_NN member function where NN is the system ICU version. The sed renames the local function.

export CC=clang CXX=clang++ ...: Upstream now use clang and building with any recent version saves a lot of space.

./mach build: Firefox now uses this python2 script to run the build and install.

./mach build --verbose: Use this alternative if you need details of which files are being compiled, together with any C or C++ flags being used.

./mach build -j4: In theory, mach will use the number of online CPU cores - but on some machines the bulk of the build will drag on as if only 1 core is present. Specifying the number of jobs (4 in this example) fixes that. Unlike traditional recommendations for running make, the exact number of cores is usually fastest - exceptionally, N+1 may be better on a well-specified modern machine. But do NOT use this if building from a term where taskset has been used to restrict the available cores.

mkdir -pv /usr/lib/mozilla/plugins: This ensures that /usr/lib/mozilla/plugins/ exists.

ln -sv ... /usr/lib/firefox/browser: This command creates a symbolic link to /usr/lib/mozilla/plugins. It's not really needed, as Firefox checks /usr/lib/mozilla/plugins by default, but the symbolic link is made to keep all the plugins installed in one folder.

Configuring Firefox

If you use a desktop environment like Gnome or KDE you may like to create a firefox.desktop file so that Firefox appears in the panel's menus. If you didn't enable startup-notification in your mozconfig change the StartupNotify line to false. As the root user:

mkdir -pv /usr/share/applications &&
mkdir -pv /usr/share/pixmaps &&

cat > /usr/share/applications/firefox.desktop << "EOF" &&
[Desktop Entry]
Name=Firefox Web Browser
Comment=Browse the World Wide Web
GenericName=Web Browser
Exec=firefox %u

ln -sfv /usr/lib/firefox/browser/chrome/icons/default/default128.png \

Configuration Information

The application settings for firefox are accessible by keying about:config in the address bar.

With this version of firefox, getting working sound can be a problem. Although upstream prefers pulseaudio, on balance using Alsa may be easier.

If you enabled Alsa for sound, you may need to alter one variable to get working sound. If you run firefox from a term and try to play something with sound you might encounter error messages like:

Sandbox: seccomp sandbox violation: pid 3941, tid 4030, syscall 16, args 48 2147767296 139909894784796 0 0 0.

That was on x86_64, on i686 the syscall number is 54. To allow this syscall, in about:config change security.sandbox.content.syscall_whitelist to 16 (or 54 if using i686).

If you use pulseaudio in a Desktop Environment, it might already be started by that DE. But if it is not, although firefox-57 managed to start it, firefox-58 does not. If you run firefox from a term, trying to play sound will encounter error messages warning Can't get cubeb context!

The fix for this is to close firefox, start pulseaudio to check it does start (if not, read the information on Configuring in PulseAudio-12.2) and restart firefox to check it is working. If it now works, add the following to your ~/.xinitrc: pulseaudio --verbose --log-target=journald& (unfortunately, on some systems this does not work).

You may wish to use multiple profiles within firefox. To do that, invoke firefox as firefox --ProfileManager. You can also check which profile is currently in use from about:profiles.


Installed Programs: firefox
Installed Libraries: Numerous libraries, browser components, plugins, extensions, and helper modules installed in /usr/lib/firefox
Installed Directory: /usr/lib/firefox and /usr/lib/mozilla

Short Descriptions


is a GTK+-3 internet browser that uses the Mozilla Gecko rendering engine.

Last updated on 2018-11-16 08:15:35 -0600