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-9.0 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, 6GB of real memory is used during the final link and the SBUs can increase significantly if the machine has to swap.

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-0.9.0, both GTK+-3.24.10 and GTK+-2.24.32, libnotify-0.7.8, nodejs-10.16.3, NSS-3.45, PulseAudio-12.2 (or alsa-lib-1.1.9 if you edit the mozconfig; now deprecated by mozilla), in either case please read the Configuration Information, rustc-1.35.0, 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 They might be tested to work, but they can be out of date or contain security holes.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-7.65.3, dbus-glib-0.110, Doxygen-1.8.16, FFmpeg-4.2 (runtime, to play mov, mp3 or mp4 files), liboauth-1.0.3, OpenJDK-12.0.2, startup-notification-0.12, Valgrind-3.15.0, Wget-1.20.3, Wireless Tools-29, libproxy, and (with the patch) Graphite2-1.3.13 and HarfBuzz-2.6.0

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.

# 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-location-service-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
# or uncomment this if you installed alsa-lib instead of PulseAudio
#ac_add_options --enable-alsa

# Comment out following options if you have not installed
# recommended dependencies:
ac_add_options --enable-system-sqlite
ac_add_options --with-system-libevent
# firefox-65 understands webp and ships with an included copy
ac_add_options --with-system-webp
ac_add_options --with-system-nspr
ac_add_options --with-system-nss
ac_add_options --with-system-icu

# Do not specify the gold linker which is not the default. It will take
# longer and use more disk space when debug symbols are disabled.

# libdavid (av1 decoder) requires nasm. Uncomment this if nasm
# has not been installed.
#ac_add_options --disable-av1

# 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

# Disabling debug symbols makes the build much smaller and a little
# faster. Comment this if you need to run a debugger. Note: This is
# required for compilation on i686.
ac_add_options --disable-debug-symbols

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

# The elf-hack is reported to cause failed installs (after successful builds)
# on some machines. It is supposed to improve startup time and it shrinks
# by a few MB - comment this if you know your machine is not affected.
ac_add_options --disable-elf-hack

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

# The default level of optimization again produces a working build with gcc.
ac_add_options --enable-optimize

# 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

# The following option unsets Telemetry Reporting. With the Addons Fiasco,
# Mozilla was found to be collecting user's data, including saved passwords and
# web form data, without users consent. Mozilla was also found shipping updates
# to systems without the user's knowledge or permission.
# As a result of this, use the following command to permanently disable
# telemetry reporting in Firefox.

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-68.0.2-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.

If you are still using ICU-63, run a sed to avoid a conflict between upstream ICU's use of CheckImpl() in their public headers and firefox's internal use of a different CheckImpl().

sed -e 's/checkImpl/checkFFImpl/g' -i js/src/vm/JSContext*.h

If you are building on i686, apply a fix to prevent Internal Compiler Errors in GCC-7+:

case $(uname -m) in
   i?86) sed -i "562 s/mips64/i386/" gfx/skia/skia/third_party/skcms/src/Transform_inl.h ;;

Now invoke the Python2 script to compile the package.

export CC=gcc CXX=g++ &&
export MOZBUILD_STATE_PATH=${PWD}/mozbuild &&
./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/

Set environment variables back to their values:


Command Explanations

sed -e 's/checkImpl/checkFFImpl/g' ...: Although the package ships with a modified version of ICU-63 and only tests that the system version, if used, is at least 63, changes from upstream 63 cause builds with the system version to fail with an error message no void JSContext::checkImpl_63 member function. The sed renames the local function. Upstream ICU-64 works around this.

export CC=gcc CXX=g++ ...: Upstream now prefer clang, but gcc is a more secure compiler and now produces reasonably-sized builds.

export MOZBUILD_STATE_PATH=${PWD}/mozbuild: The build is now supposed to tell you that it intends to create ~/.mozbuild, and offer you an option to press <ENTER> to accept this, or Ctrl-C to cancel and restart the build after specifying the directory. In practice, the message may not appear until after <ENTER> is keyed, i.e. the build stalls.

That directory is used for a (probably random) telemetry identifier. Creating this in the build directory, and deleting that after the installation, prevents it being used. If you wish to participate in telemetry, export MOZBUILD_STATE_PATH to point to its default directory.

./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 -jN: The build should, by default, use all the online CPU cores. There are two reasons to specify the number of cores, e.g. -j4 for 4 cores: First, if using all the cores causes the build to swap because you have insufficient memory (e.g. for 4 cores a build without system graphite2 and harfbuzz now uses towards 8GB of RAM). In such cases, using fewer cores can be faster. Second, on some machines the middle part of the build can drag on as if only one core is present. In those cases, specifying the number of cores may speed up the build.

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.

export CC=clang CXX=clang++ AR=llvm-ar NM=llvm-nm RANLIB=llvm-ranlib: Use this as an alternative to building with gcc and g++ if you wish to use the clang toolchain. Remember to unset these variables after the build.

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 did not. If you run firefox from a term and this problem is present, 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 2019-08-20 19:28:20 -0700