There are instructions for other platforms linked from the get the code page.
Are you a Google employee? See go/building-chrome instead.
python3
must point to a Python v3.8+ binary). Depot_tools bundles an appropriate version of Python in $depot_tools/python-bin
, if you don't have an appropriate version already on your system.libc++
is currently the only supported STL. clang
is the only officially-supported compiler, though external community members generally keep things building with gcc
. For more details, see the supported toolchains doc.Most development is done on Ubuntu (Chromium's build infrastructure currently runs 22.04, Jammy Jellyfish). There are some instructions for other distros below, but they are mostly unsupported, but installation instructions can be found in Docker.
depot_tools
Clone the depot_tools
repository:
$ git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
Add depot_tools
to the beginning of your PATH
(you will probably want to put this in your ~/.bashrc
or ~/.zshrc
). Assuming you cloned depot_tools
to /path/to/depot_tools
:
$ export PATH="/path/to/depot_tools:$PATH"
When cloning depot_tools
to your home directory do not use ~
on PATH, otherwise gclient runhooks
will fail to run. Rather, you should use either $HOME
or the absolute path:
$ export PATH="${HOME}/depot_tools:$PATH"
Create a chromium
directory for the checkout and change to it (you can call this whatever you like and put it wherever you like, as long as the full path has no spaces):
$ mkdir ~/chromium && cd ~/chromium
Run the fetch
tool from depot_tools to check out the code and its dependencies.
$ fetch --nohooks chromium
fetch
won’t work without a Nix shell. Clone the tools repo with git
, then run nix-shell tools/nix/shell.nix
.If you don't want the full repo history, you can save a lot of time by adding the --no-history
flag to fetch
.
Expect the command to take 30 minutes on even a fast connection, and many hours on slower ones.
If you've already installed the build dependencies on the machine (from another checkout, for example), you can omit the --nohooks
flag and fetch
will automatically execute gclient runhooks
at the end.
When fetch
completes, it will have created a hidden .gclient
file and a directory called src
in the working directory. The remaining instructions assume you have switched to the src
directory:
$ cd src
Once you have checked out the code, and assuming you're using Ubuntu, run build/install-build-deps.sh
$ ./build/install-build-deps.sh
You may need to adjust the build dependencies for other distros. There are some notes at the end of this document, but we make no guarantees for their accuracy.
Once you've run install-build-deps
at least once, you can now run the Chromium-specific hooks, which will download additional binaries and other things you might need:
$ gclient runhooks
Optional: You can also install API keys if you want your build to talk to some Google services, but this is not necessary for most development and testing purposes.
Chromium uses Ninja as its main build tool along with a tool called GN to generate .ninja
files. You can create any number of build directories with different configurations. To create a build directory, run:
$ gn gen out/Default
Default
with another name, but it should be a subdirectory of out
.gn help
on the command line or read the quick start guide.This section contains some things you can change to speed up your builds, sorted so that the things that make the biggest difference are first.
Chromium's build can be sped up significantly by using a remote execution system compatible with REAPI. This allows you to benefit from remote caching and executing many build actions in parallel on a shared cluster of workers.
For contributors who have tryjob access , please ask a Googler to email [email protected] on your behalf to access RBE backend paid by Google. Note that reclient for external contributors is a best-effort process. We do not guarantee when you will be invited. Reach out to [email protected] if you have any questions about reclient usage.
To get started, you need access to an REAPI-compatible backend. The following instructions assume that you received an invitation from Google to use Chromium's RBE service and were granted access to it. However, you are welcome to use any of the other compatible backends, in which case you will have to adapt the following instructions regarding the authentication method, instance name, etc. to work with your backend.
Chromium‘s build uses a client developed by Google called reclient to remotely execute build actions. If you would like to use reclient
with RBE, you’ll first need to:
gcloud auth login --update-adc
and login with your authorized account. Ignore the message about the --update-adc
flag being deprecated.Next, you'll have to specify your rbe_instance
in your .gclient
configuration to use the correct one for Chromium contributors:
solutions = [ { ..., "custom_vars": { # This is the correct instance name for using Chromium's RBE service. # You can only use it if you were granted access to it. If you use your # own REAPI-compatible backend, you will need to change this accordingly # to its requirements. "rbe_instance": "projects/rbe-chromium-untrusted/instances/default_instance", }, }, ]
And run gclient sync
. This will regenerate the config files in buildtools/reclient_cfgs
to use the rbe_instance
that you just added to your .gclient
file.
Then, add the following GN args to your args.gn
:
use_remoteexec = true reclient_cfg_dir = "../../buildtools/reclient_cfgs/linux"
rbe_cfg_dir = "../../buildtools/reclient_cfgs_linux"
That‘s it. Remember to always use autoninja
for building Chromium as described below, which handles the startup and shutdown of the reproxy daemon process that’s required during the build, instead of directly invoking ninja
.
By default, the build includes support for Native Client (NaCl), but most of the time you won‘t need it. You can set the GN argument enable_nacl=false
and it won’t be built.
By default GN produces a build with all of the debug assertions enabled (is_debug=true
) and including full debug info (symbol_level=2
). Setting symbol_level=1
will produce enough information for stack traces, but not line-by-line debugging. Setting symbol_level=0
will include no debug symbols at all. Either will speed up the build compared to full symbols.
Due to its extensive use of templates, the Blink code produces about half of our debug symbols. If you don‘t ever need to debug Blink, you can set the GN arg blink_symbol_level=0
. Similarly, if you don’t need to debug v8 you can improve build speeds by setting the GN arg v8_symbol_level=0
.
Icecc is the distributed compiler with a central scheduler to share build load. Currently, many external contributors use it. e.g. Intel, Opera, Samsung (this is not useful if you're using Reclient).
In order to use icecc
, set the following GN args:
use_debug_fission=false is_clang=false
See these links for more on the bundled_binutils limitation, the debug fission limitation.
Using the system linker may also be necessary when using glibc 2.21 or newer. See related bug.
You can use ccache to speed up local builds (again, this is not useful if you're using Reclient).
Increase your ccache hit rate by setting CCACHE_BASEDIR
to a parent directory that the working directories all have in common (e.g., /home/yourusername/development
). Consider using CCACHE_SLOPPINESS=include_file_mtime
(since if you are using multiple working directories, header times in svn sync'ed portions of your trees will be different - see the ccache troubleshooting section for additional information). If you use symbolic links from your home directory to get to the local physical disk directory where you keep those working development directories, consider putting
alias cd="cd -P"
in your .bashrc
so that $PWD
or cwd
always refers to a physical, not logical directory (and make sure CCACHE_BASEDIR
also refers to a physical parent).
If you tune ccache correctly, a second working directory that uses a branch tracking trunk and is up to date with trunk and was gclient sync'ed at about the same time should build chrome in about 1/3 the time, and the cache misses as reported by ccache -s
should barely increase.
This is especially useful if you use git-worktree and keep multiple local working directories going at once.
You can use tmpfs for the build output to reduce the amount of disk writes required. I.e. mount tmpfs to the output directory where the build output goes:
As root:
mount -t tmpfs -o size=20G,nr_inodes=40k,mode=1777 tmpfs /path/to/out
Quick and dirty benchmark numbers on a HP Z600 (Intel core i7, 16 cores hyperthreaded, 12 GB RAM)
The Chrome binary contains embedded symbols by default. You can reduce its size by using the Linux strip
command to remove this debug information. You can also reduce binary size and turn on all optimizations by enabling official build mode, with the GN arg is_official_build = true
.
Build Chromium (the “chrome” target) with Ninja using the command:
$ autoninja -C out/Default chrome
(autoninja
is a wrapper that automatically provides optimal values for the arguments passed to ninja
.)
You can get a list of all of the other build targets from GN by running gn ls out/Default
from the command line. To compile one, pass the GN label to Ninja with no preceding “//” (so, for //chrome/test:unit_tests
use autoninja -C out/Default chrome/test:unit_tests
).
Ninja supports a special syntax ^
to compile a single object file specyfing the source file. For example, autoninja -C out/Default ../../base/logging.cc^
compiles obj/base/base/logging.o
.
In addition to foo.cc^
, Siso also supports foo.h^
syntax to compile the corresponding foo.o
if it exists.
Once it is built, you can simply run the browser:
$ out/Default/chrome
If you're using a remote machine that supports Chrome Remote Desktop, you can add this to your .bashrc / .bash_profile.
if [[ -z "${DISPLAY}" ]]; then # In reality, Chrome Remote Desktop starts with 20 and increases until it # finds an available ID [1]. So this isn't guaranteed to always work, but # should work on the vast majoriy of cases. # # [1] https://source.chromium.org/chromium/chromium/src/+/main:remoting/host/linux/linux_me2me_host.py;l=112;drc=464a632e21bcec76c743930d4db8556613e21fd8 export DISPLAY=:20 fi
This means if you launch Chrome from an SSH session, the UI output will be available in Chrome Remote Desktop.
Tests are split into multiple test targets based on their type and where they exist in the directory structure. To see what target a given unit test or browser test file corresponds to, the following command can be used:
$ gn refs out/Default --testonly=true --type=executable --all chrome/browser/ui/browser_list_unittest.cc //chrome/test:unit_tests
In the example above, the target is unit_tests. The unit_tests binary can be built by running the following command:
$ autoninja -C out/Default unit_tests
You can run the tests by running the unit_tests binary. You can also limit which tests are run using the --gtest_filter
arg, e.g.:
$ out/Default/unit_tests --gtest_filter="BrowserListUnitTest.*"
You can find out more about GoogleTest at its GitHub page.
To update an existing checkout, you can run
$ git rebase-update $ gclient sync
The first command updates the primary Chromium source repository and rebases any of your local branches on top of tip-of-tree (aka the Git branch origin/main
). If you don't want to use this script, you can also just use git pull
or other common Git commands to update the repo.
The second command syncs dependencies to the appropriate versions and re-runs hooks as needed.
If, during the final link stage:
LINK out/Debug/chrome
You get an error like:
collect2: ld terminated with signal 6 Aborted terminate called after throwing an instance of 'std::bad_alloc' collect2: ld terminated with signal 11 [Segmentation fault], core dumped
or:
LLVM ERROR: out of memory
you are probably running out of memory when linking. You must use a 64-bit system to build. Try the following build settings (see GN build configuration for other settings):
is_debug = false
symbol_level = 0
is_component_build = true
vm.max_map_count
value from default (like 65530) to for example 262144. You can run the sudo sysctl -w vm.max_map_count=262144
command to set it in the current session from the shell, or add the vm.max_map_count=262144
to /etc/sysctl.conf to save it permanently.If you want to contribute to the effort toward a Chromium-based browser for Linux, please check out the Linux Development page for more information.
Instead of running install-build-deps.sh
to install build dependencies, run:
$ sudo pacman -S --needed python perl gcc gcc-libs bison flex gperf pkgconfig \ nss alsa-lib glib2 gtk3 nspr freetype2 cairo dbus xorg-server-xvfb \ xorg-xdpyinfo
For the optional packages on Arch Linux:
php-cgi
is provided with pacman
wdiff
is not in the main repository but dwdiff
is. You can get wdiff
in AUR/yaourt
First install the file
and lsb-release
commands for the script to run properly:
$ sudo apt-get install file lsb-release
Then invoke install-build-deps.sh with the --no-arm
argument, because the ARM toolchain doesn't exist for this configuration:
$ sudo install-build-deps.sh --no-arm
Instead of running build/install-build-deps.sh
, run:
su -c 'yum install git python bzip2 tar pkgconfig atk-devel alsa-lib-devel \ bison binutils brlapi-devel bluez-libs-devel bzip2-devel cairo-devel \ cups-devel dbus-devel dbus-glib-devel expat-devel fontconfig-devel \ freetype-devel gcc-c++ glib2-devel glibc.i686 gperf glib2-devel \ gtk3-devel java-1.*.0-openjdk-devel libatomic libcap-devel libffi-devel \ libgcc.i686 libjpeg-devel libstdc++.i686 libX11-devel libXScrnSaver-devel \ libXtst-devel libxkbcommon-x11-devel ncurses-compat-libs nspr-devel nss-devel \ pam-devel pango-devel pciutils-devel pulseaudio-libs-devel zlib.i686 httpd \ mod_ssl php php-cli python-psutil wdiff xorg-x11-server-Xvfb'
The fonts needed by Blink's web tests can be obtained by following these instructions. For the optional packages:
php-cgi
is provided by the php-cli
package.sun-java6-fonts
is covered by the instructions linked above.You can just run emerge www-client/chromium
.
To get a shell with the dev environment:
$ nix-shell tools/nix/shell.nix
To run a command in the dev environment:
$ NIX_SHELL_RUN='autoninja -C out/Default chrome' nix-shell tools/nix/shell.nix
To set up clangd with remote indexing support, run the command below, then copy the path into your editor config:
$ NIX_SHELL_RUN='readlink /usr/bin/clangd' nix-shell tools/nix/shell.nix
Use zypper
command to install dependencies:
(openSUSE 11.1 and higher)
sudo zypper in subversion pkg-config python perl bison flex gperf \ mozilla-nss-devel glib2-devel gtk-devel wdiff lighttpd gcc gcc-c++ \ mozilla-nspr mozilla-nspr-devel php5-fastcgi alsa-devel libexpat-devel \ libjpeg-devel libbz2-devel
For 11.0, use libnspr4-0d
and libnspr4-dev
instead of mozilla-nspr
and mozilla-nspr-devel
, and use php5-cgi
instead of php5-fastcgi
.
(openSUSE 11.0)
sudo zypper in subversion pkg-config python perl \ bison flex gperf mozilla-nss-devel glib2-devel gtk-devel \ libnspr4-0d libnspr4-dev wdiff lighttpd gcc gcc-c++ libexpat-devel \ php5-cgi alsa-devel gtk3-devel jpeg-devel
The Ubuntu package sun-java6-fonts
contains a subset of Java of the fonts used. Since this package requires Java as a prerequisite anyway, we can do the same thing by just installing the equivalent openSUSE Sun Java package:
sudo zypper in java-1_6_0-sun
WebKit is currently hard-linked to the Microsoft fonts. To install these using zypper
sudo zypper in fetchmsttfonts pullin-msttf-fonts
To make the fonts installed above work, as the paths are hardcoded for Ubuntu, create symlinks to the appropriate locations:
sudo mkdir -p /usr/share/fonts/truetype/msttcorefonts sudo ln -s /usr/share/fonts/truetype/arial.ttf /usr/share/fonts/truetype/msttcorefonts/Arial.ttf sudo ln -s /usr/share/fonts/truetype/arialbd.ttf /usr/share/fonts/truetype/msttcorefonts/Arial_Bold.ttf sudo ln -s /usr/share/fonts/truetype/arialbi.ttf /usr/share/fonts/truetype/msttcorefonts/Arial_Bold_Italic.ttf sudo ln -s /usr/share/fonts/truetype/ariali.ttf /usr/share/fonts/truetype/msttcorefonts/Arial_Italic.ttf sudo ln -s /usr/share/fonts/truetype/comic.ttf /usr/share/fonts/truetype/msttcorefonts/Comic_Sans_MS.ttf sudo ln -s /usr/share/fonts/truetype/comicbd.ttf /usr/share/fonts/truetype/msttcorefonts/Comic_Sans_MS_Bold.ttf sudo ln -s /usr/share/fonts/truetype/cour.ttf /usr/share/fonts/truetype/msttcorefonts/Courier_New.ttf sudo ln -s /usr/share/fonts/truetype/courbd.ttf /usr/share/fonts/truetype/msttcorefonts/Courier_New_Bold.ttf sudo ln -s /usr/share/fonts/truetype/courbi.ttf /usr/share/fonts/truetype/msttcorefonts/Courier_New_Bold_Italic.ttf sudo ln -s /usr/share/fonts/truetype/couri.ttf /usr/share/fonts/truetype/msttcorefonts/Courier_New_Italic.ttf sudo ln -s /usr/share/fonts/truetype/impact.ttf /usr/share/fonts/truetype/msttcorefonts/Impact.ttf sudo ln -s /usr/share/fonts/truetype/times.ttf /usr/share/fonts/truetype/msttcorefonts/Times_New_Roman.ttf sudo ln -s /usr/share/fonts/truetype/timesbd.ttf /usr/share/fonts/truetype/msttcorefonts/Times_New_Roman_Bold.ttf sudo ln -s /usr/share/fonts/truetype/timesbi.ttf /usr/share/fonts/truetype/msttcorefonts/Times_New_Roman_Bold_Italic.ttf sudo ln -s /usr/share/fonts/truetype/timesi.ttf /usr/share/fonts/truetype/msttcorefonts/Times_New_Roman_Italic.ttf sudo ln -s /usr/share/fonts/truetype/verdana.ttf /usr/share/fonts/truetype/msttcorefonts/Verdana.ttf sudo ln -s /usr/share/fonts/truetype/verdanab.ttf /usr/share/fonts/truetype/msttcorefonts/Verdana_Bold.ttf sudo ln -s /usr/share/fonts/truetype/verdanai.ttf /usr/share/fonts/truetype/msttcorefonts/Verdana_Italic.ttf sudo ln -s /usr/share/fonts/truetype/verdanaz.ttf /usr/share/fonts/truetype/msttcorefonts/Verdana_Bold_Italic.ttf
The Ubuntu package sun-java6-fonts
contains a subset of Java of the fonts used. Since this package requires Java as a prerequisite anyway, we can do the same thing by just installing the equivalent openSUSE Sun Java package:
sudo zypper in java-1_6_0-sun
WebKit is currently hard-linked to the Microsoft fonts. To install these using zypper
sudo zypper in fetchmsttfonts pullin-msttf-fonts
To make the fonts installed above work, as the paths are hardcoded for Ubuntu, create symlinks to the appropriate locations:
sudo mkdir -p /usr/share/fonts/truetype/msttcorefonts sudo ln -s /usr/share/fonts/truetype/arial.ttf /usr/share/fonts/truetype/msttcorefonts/Arial.ttf sudo ln -s /usr/share/fonts/truetype/arialbd.ttf /usr/share/fonts/truetype/msttcorefonts/Arial_Bold.ttf sudo ln -s /usr/share/fonts/truetype/arialbi.ttf /usr/share/fonts/truetype/msttcorefonts/Arial_Bold_Italic.ttf sudo ln -s /usr/share/fonts/truetype/ariali.ttf /usr/share/fonts/truetype/msttcorefonts/Arial_Italic.ttf sudo ln -s /usr/share/fonts/truetype/comic.ttf /usr/share/fonts/truetype/msttcorefonts/Comic_Sans_MS.ttf sudo ln -s /usr/share/fonts/truetype/comicbd.ttf /usr/share/fonts/truetype/msttcorefonts/Comic_Sans_MS_Bold.ttf sudo ln -s /usr/share/fonts/truetype/cour.ttf /usr/share/fonts/truetype/msttcorefonts/Courier_New.ttf sudo ln -s /usr/share/fonts/truetype/courbd.ttf /usr/share/fonts/truetype/msttcorefonts/Courier_New_Bold.ttf sudo ln -s /usr/share/fonts/truetype/courbi.ttf /usr/share/fonts/truetype/msttcorefonts/Courier_New_Bold_Italic.ttf sudo ln -s /usr/share/fonts/truetype/couri.ttf /usr/share/fonts/truetype/msttcorefonts/Courier_New_Italic.ttf sudo ln -s /usr/share/fonts/truetype/impact.ttf /usr/share/fonts/truetype/msttcorefonts/Impact.ttf sudo ln -s /usr/share/fonts/truetype/times.ttf /usr/share/fonts/truetype/msttcorefonts/Times_New_Roman.ttf sudo ln -s /usr/share/fonts/truetype/timesbd.ttf /usr/share/fonts/truetype/msttcorefonts/Times_New_Roman_Bold.ttf sudo ln -s /usr/share/fonts/truetype/timesbi.ttf /usr/share/fonts/truetype/msttcorefonts/Times_New_Roman_Bold_Italic.ttf sudo ln -s /usr/share/fonts/truetype/timesi.ttf /usr/share/fonts/truetype/msttcorefonts/Times_New_Roman_Italic.ttf sudo ln -s /usr/share/fonts/truetype/verdana.ttf /usr/share/fonts/truetype/msttcorefonts/Verdana.ttf sudo ln -s /usr/share/fonts/truetype/verdanab.ttf /usr/share/fonts/truetype/msttcorefonts/Verdana_Bold.ttf sudo ln -s /usr/share/fonts/truetype/verdanai.ttf /usr/share/fonts/truetype/msttcorefonts/Verdana_Italic.ttf sudo ln -s /usr/share/fonts/truetype/verdanaz.ttf /usr/share/fonts/truetype/msttcorefonts/Verdana_Bold_Italic.ttf
And then for the Java fonts:
sudo mkdir -p /usr/share/fonts/truetype/ttf-lucida sudo find /usr/lib*/jvm/java-1.6.*-sun-*/jre/lib -iname '*.ttf' -print \ -exec ln -s {} /usr/share/fonts/truetype/ttf-lucida \;
While it is not a common setup, Chromium compilation should work from within a Docker container. If you choose to compile from within a container for whatever reason, you will need to make sure that the following tools are available:
curl
git
lsb_release
python3
sudo
file
There may be additional Docker-specific issues during compilation. See this bug for additional details on this.
Note: Clone depot_tools first.
/path/to/chromium/
.# Use an official Ubuntu base image with Docker already installed FROM ubuntu:22.04 # Set environment variables ENV DEBIAN_FRONTEND=noninteractive # Install Mantatory tools (curl git python3) and optional tools (vim sudo) RUN apt-get update && \ apt-get install -y curl git lsb-release python3 git file vim sudo && \ rm -rf /var/lib/apt/lists/* # Export depot_tools path ENV PATH="/depot_tools:${PATH}" # Configure git for safe.directory RUN git config --global --add safe.directory /depot_tools && \ git config --global --add safe.directory /chromium/src # Set the working directory to the existing Chromium source directory. # This can be either "/chromium/src" or "/chromium". WORKDIR /chromium/src # Expose any necessary ports (if needed) # EXPOSE 8080 # Create a dummy user and group to avoid permission issues RUN groupadd -g 1001 chrom-d && \ useradd -u 1000 -g 1001 -m chrom-d # Create normal user with name "chrom-d". Optional and you can use root but # not advised. USER chrom-d # Start Chromium Builder "chrom-d" (modify this command as needed) # CMD ["autoninja -C out/Default chrome"] CMD ["bash"]
# chrom-b is just a name; You can change it but you must reflect the renaming # in all commands below $ docker build -t chrom-b .
$ docker run -it \ # Run docker interactively --name chrom-b \ # with name "chrom-b" -u root \ # with user root -v /path/on/machine/to/chromium:/chromium \ # With chromium folder mounted -v /path/on/machine/to/depot_tools:/depot_tools \ # With depot_tools mounted chrom-b # Run container with image name "chrom-b"
#
) to avoid breaking the command../build/install-build-deps.sh
Before running hooks: Ensure that all directories within third_party
are added as safe directories in Git. This is required when running in the container because the ownership of the src/
directory (e.g., chrom-b
) differs from the current user (e.g., root
). To prevent Git warnings about “dubious ownership” run the following command after installing the dependencies:
# Loop through each directory in /chromium/src/third_party and add # them as safe directories in Git $ for dir in /chromium/src/third_party/*; do if [ -d "$dir" ]; then git config --global --add safe.directory "$dir" fi done
Exit container
Save container image with tag-id name dpv1.0
. Run this on the machine, not in container
# Get docker running/stopped containers, copy the "chrom-b" id $ docker container ls -a # Save/tag running docker container with name "chrom-b" with "dpv1.0" # You can choose any tag name you want but propagate name accordingly # You will need to create new tags when working on different parts of # chromium which requires installing additional dependencies $ docker commit <ID from above step> chrom-b:dpv1.0 # Optional, just saves space by deleting unnecessary images $ docker image rmi chrom-b:latest && docker image prune \ && docker container prune && docker builder prune
$ docker run --rm \ # close instance upon exit -it \ # Run docker interactively --name chrom-b \ # with name "chrom-b" -u $(id -u):$(id -g) \ # Run container as a non-root user with same UID & GID -v /path/on/machine/to/chromium:/chromium \ # With chromium folder mounted -v /path/on/machine/to/depot_tools:/depot_tools \ # With depot_tools mounted chrom-b:dpv1.0 # Run container with image name "chrom-b" and tag dpv1.0
#
) to avoid breaking the command.