Compile Swift for Linux with its Toolchain and Package Manager

If you are unable to install Swift with pre-built binaries, you can compile it instead.  Compiling is a lot more complex and confusing than simply installing prebuilt binaries and I found that a lot of instructions do not build the Swift package manager which I consider to be a necessity when build anything more complex than a simple hello world application.  In this post we look at how we can build Swift with its full toolchain and package manager.

Install Dependencies

The first thing we need to do is to make sure we have all of the dependencies required installed.  The following command includes all dependencies I have needed to install on different flavors of Linux.  You will find that your distribution probably already has a lot of these preinstalled but to make sure you have everything, run this command.

sudo apt-get install git cmake ninja-build clang python uuid-dev libicu-dev icu-devtools libedit-dev libxml2-dev libsqlite3-dev swig libpython-dev libncurses5-dev pkg-config libcurl4-openssl-dev systemtap-sdt-dev tzdata rsync python-pip

If you want to build the documentation, you will need to install Sphinx as well.  This can be done with the following command:

 pip install Sphinx

Now that we have all of the dependencies installed, we need to get the swift source code.

Swift Source

To download the Swift source code, we will want to create a directory to download it too, change to that directory and then run the git command to get the source.  The following commands will download the swift source to a directory name swift-source.

mkdir swift-source

cd swift-source

git clone https://github.com/apple/swift.git

./swift/utils/update-checkout --clone

Now that we have the source and cloned everything we need, lets build swift.

Build Swift 

Before you begin building Swift, know that it is going to take hours to build.  The exact time will depend on the type of system you are building it on.  The following command will build Swift, its toolchain and the package manager:

./swift/utils/build-script --preset=buildbot_swiftpm_linux_platform,tools=RA,stdlib=RA

Once this has built everything, which could take several hours, we will want to install it similar to what we did with the pre-built binaries in this post:  

Installing Swift

Now that we have built Swift from source, we are ready to install it and put it in our path so we can execute them easily.  I like to install the under the /opt directory, others prefer installing it under the /usr/local/sharedirectory.  What directory you put it under is totally up to you.  I will walk you through installing it under the /optdirectory, if you would like to put it someplace else simply replace the “/opt” in the paths with your install directory.  

Now let’s change to the /opt directory and create a directory named swift.  Once the swift directory is created, we will also need to change the permissions for the directory so we can read, write and execute files.  The following commands will do this:

cd /opt

sudo mkdir swift

sudo chmod 777 swift

The command chmod 777 swift will add read, write and execute permissions for all users of this computer.  I like to use this mode because then any user on the system can use it, however this can be considered a security issue because it also means anyone can modify the files.  Use this at your own risk and for production systems I would really look at who needs permissions for this directly and lock it down more.

Now we will need to move the Swift binaries that we downloaded to the swift directory.  To do this we will change to the swift directory, create a new directory for our build, change to the directory and copy the files over.  For this article I am building the 5.3-dev version of swift therefore I am using that for my directory name.  The following commands will do this:

cd swift

mkdir swift-5.3-dev

cd swift-5.3-dev

cp -R ~/swift-source/build/buildbot_incremental/toolchain-linux-x86_64/* ./



Now we will want to make a symlink to this directory called swift-current.  The reason for this is we will want to add an entry to our PATH environmental variable so the operating system can find the Swift executables without us needing to enter the full path.  If we set up this entry using the swift-current path rather than the swift.5.3-dev path.  This will allow us, when we install new versions of Swift, to simply change where the swift-current symlink points to and have everything work.   We will do this with the following command:

sudo ln -s /opt/swift/ swift-5.3-dev swift-current

Now we will need to create the entry in our PATH variable.  To do this you will want add the add /opt/swift/swift-current/usr/bin/ directory to the PATH variable in our .profile file located in your home directory.  Then update the environment The following commands will do this:

cd ~

echo 'export PATH=$PATH:/opt/swift/swift-current/usr/bin'  >> .profile

source ~/.profile

The last thing we need to do is to verify swift has been successfully installed. To do this, we can run the following command:

swift –version

The output should look something like this but with the version of swift that you installed

Swift version 5.2.2 (swift-5.2.2-RELEASE)

Target: x86_64-unknown-linux-gnu

Congratulations, you have now successfully installed Swift.