# Build Instructions (Linux)

Follow the guidelines below for building Electron on Linux.

## Prerequisites

* At least 25GB disk space and 8GB RAM.
* Python 2.7.x. Some distributions like CentOS 6.x still use Python 2.6.x
  so you may need to check your Python version with `python -V`.

  Please also ensure that your system and Python version support at least TLS 1.2.
  For a quick test, run the following script:

  ```sh
  $ npm run check-tls
  ```

  If the script returns that your configuration is using an outdated security
  protocol, use your system's package manager to update Python to the latest
  version in the 2.7.x branch. Alternatively, visit https://www.python.org/downloads/
  for detailed instructions.

* Node.js. There are various ways to install Node. You can download
  source code from [nodejs.org](https://nodejs.org) and compile it.
  Doing so permits installing Node on your own home directory as a standard user.
  Or try repositories such as [NodeSource](https://nodesource.com/blog/nodejs-v012-iojs-and-the-nodesource-linux-repositories).
* [clang](https://clang.llvm.org/get_started.html) 3.4 or later.
* Development headers of GTK+ and libnotify.

On Ubuntu, install the following libraries:

```sh
$ sudo apt-get install build-essential clang libdbus-1-dev libgtk-3-dev \
                       libnotify-dev libgnome-keyring-dev libgconf2-dev \
                       libasound2-dev libcap-dev libcups2-dev libxtst-dev \
                       libxss1 libnss3-dev gcc-multilib g++-multilib curl \
                       gperf bison python-dbusmock openjdk-8-jre
```

On RHEL / CentOS, install the following libraries:

```sh
$ sudo yum install clang dbus-devel gtk3-devel libnotify-devel \
                   libgnome-keyring-devel xorg-x11-server-utils libcap-devel \
                   cups-devel libXtst-devel alsa-lib-devel libXrandr-devel \
                   GConf2-devel nss-devel python-dbusmock openjdk-8-jre
```

On Fedora, install the following libraries:

```sh
$ sudo dnf install clang dbus-devel gtk3-devel libnotify-devel \
                   libgnome-keyring-devel xorg-x11-server-utils libcap-devel \
                   cups-devel libXtst-devel alsa-lib-devel libXrandr-devel \
                   GConf2-devel nss-devel python-dbusmock openjdk-8-jre
```

Other distributions may offer similar packages for installation via package
managers such as pacman. Or one can compile from source code.

### Cross compilation

If you want to build for an `arm` target you should also install the following
dependencies:

```sh
$ sudo apt-get install libc6-dev-armhf-cross linux-libc-dev-armhf-cross \
                       g++-arm-linux-gnueabihf
```

Similarly for `arm64`, install the following:

```sh
$ sudo apt-get install libc6-dev-arm64-cross linux-libc-dev-arm64-cross \
                       g++-aarch64-linux-gnu
```

And to cross-compile for `arm` or `ia32` targets, you should pass the
`target_cpu` parameter to `gn gen`:

```sh
$ gn gen out/Debug --args='import(...) target_cpu="arm"'
```

## Building

See [Build Instructions: GN](build-instructions-gn.md)

## Troubleshooting

### Error While Loading Shared Libraries: libtinfo.so.5

Prebuilt `clang` will try to link to `libtinfo.so.5`. Depending on the host
architecture, symlink to appropriate `libncurses`:

```sh
$ sudo ln -s /usr/lib/libncurses.so.5 /usr/lib/libtinfo.so.5
```

## Advanced topics

The default building configuration is targeted for major desktop Linux
distributions. To build for a specific distribution or device, the following
information may help you.

### Using system `clang` instead of downloaded `clang` binaries

By default Electron is built with prebuilt
[`clang`](https://clang.llvm.org/get_started.html) binaries provided by the
Chromium project. If for some reason you want to build with the `clang`
installed in your system, you can specify the `clang_base_path` argument in the
GN args.

For example if you installed `clang` under `/usr/local/bin/clang`:

```sh
$ gn gen out/Debug --args='import("//electron/build/args/debug.gn") clang_base_path = "/usr/local/bin"'
```

### Using compilers other than `clang`

Building Electron with compilers other than `clang` is not supported.
