Build status:

Code coverage:

Julia is a high-level, high-performance dynamic language for technical computing. The main homepage for Julia can be found at julialang.org. This is the GitHub repository of Julia source code, including instructions for compiling and installing Julia, below.

• Homepage: https://julialang.org
• Binaries: https://julialang.org/downloads/
• Documentation: https://docs.julialang.org/
• Packages: https://pkg.julialang.org/
• Source code: https://github.com/JuliaLang/julia
• Git clone URL: git:https://github.com/JuliaLang/julia.git
• Discussion forum: https://discourse.julialang.org
• Mailing lists: https://julialang.org/community/
• Slack: https://julialang.slack.com (get an invite from https://slackinvite.julialang.org)
• Gitter: https://gitter.im/JuliaLang/julia
• IRC: https://webchat.freenode.net/?channels=julia
• Code coverage: https://coveralls.io/r/JuliaLang/julia

New developers may find the notes in CONTRIBUTING helpful to start contributing to the Julia codebase.

• StackOverflow
• Youtube
• Twitter
• Meetup

Julia is built and tested regularly on the following platforms:

All systems marked with ✓ for CI are tested using continuous integration for every commit. Systems with ✓ for binaries have official binaries available on the downloads page and are tested regularly. The PTX backend needs a source build and the CUDAnative.jl package. The systems listed here with neither CI nor official binaries are known to build and work, but ongoing support for those platforms is dependent on community efforts. It's possible that Julia will build and work on other platforms too, and we're always looking to better our platform coverage. If you're using Julia on a platform not listed here, let us know!

First, make sure you have all the required dependencies installed. Then, acquire the source code by cloning the git repository:

git clone git:https://github.com/JuliaLang/julia.git

(If you are behind a firewall, you may need to use the https protocol instead of the git protocol:

git config --global url."https://".insteadOf git:https://

Be sure to also configure your system to use the appropriate proxy settings, e.g. by setting the https_proxy and http_proxy variables.)

By default you will be building the latest unstable version of Julia. However, most users should use the most recent stable version of Julia, which is currently the 0.6 series of releases. You can get this version by changing to the Julia directory and running

git checkout v0.6.2

Now run make to build the julia executable. To perform a parallel build, use make -j N and supply the maximum number of concurrent processes. (See Platform Specific Build Notes for details.) When compiled the first time, it will automatically download and build its external dependencies. This takes a while, but only has to be done once. If the defaults in the build do not work for you, and you need to set specific make parameters, you can save them in Make.user. The build will automatically check for the existence of Make.user and use it if it exists. Building Julia requires 1.5GiB of disk space and approximately 700MiB of virtual memory.

For builds of julia starting with 0.5.0-dev, you can create out-of-tree builds of Julia by specifying make O=<build-directory> configure on the command line. This will create a directory mirror, with all of the necessary Makefiles to build Julia, in the specified directory. These builds will share the source files in Julia and deps/srccache. Each out-of-tree build directory can have its own Make.user file to override the global Make.user file in the top-level folder.

If you need to build Julia on a machine without internet access, use make -C deps getall to download all the necessary files. Then, copy the julia directory over to the target environment and build with make.

Note: The build process will fail badly if any of the build directory's parent directories have spaces or other shell meta-characters such as $ or : in their names (this is due to a limitation in GNU make).

Once it is built, you can run the julia executable using its full path in the directory created above (the julia directory). To run julia from anywhere you can:

• add an alias (in bash: echo "alias julia='/path/to/install/folder/bin/julia'" >> ~/.bashrc && source ~/.bashrc), or

• add a soft link to the julia executable in the julia directory to /usr/local/bin (or any suitable directory already in your path), or

• add the julia directory to your executable path for this shell session (in bash: export PATH="$(pwd):$PATH" ; in csh or tcsh: set path= ( $path $cwd ) ), or

• add the julia directory to your executable path permanently (e.g. in .bash_profile), or

• write prefix=/path/to/install/folder into Make.user and then run make install. If there is a version of Julia already installed in this folder, you should delete it before running make install.

Now you should be able to run Julia like this:

julia

If everything works correctly, you will see a Julia banner and an interactive prompt into which you can enter expressions for evaluation. (Errors related to libraries might be caused by old, incompatible libraries sitting around in your PATH. In this case, try moving the julia directory earlier in the PATH).

Your first test of Julia determines whether your build is working properly. From the UNIX/Windows command prompt inside the julia source directory, type make testall. You should see output that lists a series of running tests; if they complete without error, you should be in good shape to start using Julia.

You can read about getting started in the manual.

If you are building a Julia package for distribution on Linux, OS X, or Windows, take a look at the detailed notes in DISTRIBUTING.md.

If you have previously downloaded julia using git clone, you can update the existing source tree using git pull rather than starting anew:

cd julia
git pull && make

Assuming that you had made no changes to the source tree that will conflict with upstream updates, these commands will trigger a build to update to the latest version.

1. Over time, the base library may accumulate enough changes such that the bootstrapping process in building the system image will fail. If this happens, the build may fail with an error like

    *** This error is usually fixed by running 'make clean'. If the error persists, try 'make cleanall' ***

   As described, running make clean && make is usually sufficient. Occasionally, the stronger cleanup done by make cleanall is needed.

2. New versions of external dependencies may be introduced which may occasionally cause conflicts with existing builds of older versions.

   a. Special make targets exist to help wipe the existing build of a dependency. For example, make -C deps clean-llvm will clean out the existing build of llvm so that llvm will be rebuilt from the downloaded source distribution the next time make is called. make -C deps distclean-llvm is a stronger wipe which will also delete the downloaded source distribution, ensuring that a fresh copy of the source distribution will be downloaded and that any new patches will be applied the next time make is called.

   b. To delete existing binaries of julia and all its dependencies, delete the ./usr directory in the source tree.

3. If you've updated OS X recently, be sure to run xcode-select --install to update the command line tools. Otherwise, you could run into errors for missing headers and libraries, such as ld: library not found for -lcrt1.10.6.o.

4. If you've moved the source directory, you might get errors such as CMake Error: The current CMakeCache.txt directory ... is different than the directory ... where CMakeCache.txt was created., in which case you may delete the offending dependency under deps

5. In extreme cases, you may wish to reset the source tree to a pristine state. The following git commands may be helpful:

    git reset --hard #Forcibly remove any changes to any files under version control
    git clean -x -f -d #Forcibly remove any file or directory not under version control

   To avoid losing work, make sure you know what these commands do before you run them. git will not be able to undo these changes!

Julia does not install anything outside the directory it was cloned into. Julia can be completely uninstalled by deleting this directory. Julia packages are installed in ~/.julia by default, and can be uninstalled by deleting ~/.julia.

• GCC version 4.7 or later is required to build Julia.
• To use external shared libraries not in the system library search path, set USE_SYSTEM_XXX=1 and LDFLAGS=-Wl,-rpath,/path/to/dir/contains/libXXX.so in Make.user.
  • Instead of setting LDFLAGS, putting the library directory into the environment variable LD_LIBRARY_PATH (at both compile and run time) also works.
• See also the external dependencies.

Julia can be built for a non-generic architecture by configuring the ARCH Makefile variable. See the appropriate section of Make.inc for additional customization options, such as MARCH and JULIA_CPU_TARGET.

For example, to build for Pentium 4, set MARCH=pentium4 and install the necessary system libraries for linking. On Ubuntu, these may include lib32gfortran-6-dev, lib32gcc1, and lib32stdc++6, among others.

You can also set MARCH=native for a maximum-performance build customized for the current machine CPU.

The julia-deps PPA contains updated packages for Julia dependencies if you want to use system libraries instead of having them downloaded and built during the build process. See System Provided Libraries.

On RHEL/CentOS 6 systems, the default compiler (gcc 4.4) is too old to build Julia.

Install or contact your systems administrator to install a more recent version of gcc. The Scientific Linux Developer Toolset works well.