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Swift on Windows
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Swift on Windows

Windows nightlies built on Azure


Build Status
Toolchain x64 VS2017 Build Status
x64 VS2019 Build Status
Windows SDK Build Status
Android SDK Build Status

Getting Started

Downloading the nightlies

  1. We assume you are reading these instructions on the Azure DevOps page for windows-swift at
  2. Choose Pipelines > builds from the left of the dashboard.
  3. Click the most recent successful build.
  4. At the top right of this page to the right of where it says All logs there is a three dot button. Under this choose Artifacts > toolchain to download the nightly toolchain to your machine.

Installing the nightlies

  1. Extract the toolchain artifact. We assume that the toolchain will be installed to C:\Library. Extracting it to that location should give you a hierarchy that looks like C:\Library\Developer\Toolchains\unknown-Asserts-development.xctoolchain\usr\bin\swiftc.exe.
  2. In order to develop with this toolchain, you will need an installation of the Windows SDK. The easiest way to do this is to install Visual Studio. Additionally, you will need to copy a few files into the SDK to make it usable from swift.
curl -L "" -o "%UniversalCRTSdkDir%\Include\%UCRTVersion%\ucrt\module.modulemap"
curl -L "" -o "%VCToolsInstallDir%\include\module.modulemap"
curl -L "" -o "%VCToolsInstallDir%\include\visualc.apinotes"
curl -L "" -o "%UniversalCRTSdkDir%\Include\%UCRTVersion%\um\module.modulemap"
  1. You will need to add the ICU libraries for the target. The nightlies are built against ICU 63.1 from the ICU project. You can download the binaries for that from In these instructions we assume you rename the extracted icu folder icu4c-63_1-Win64-MSVC2017 to icu63_1 and move it to C:\Library.

Building and running swift code

  1. To have the required Visual Studio toolchain available ensure you use the x64 Native Tools Command Prompt for VS 2017 that came with Visual Studio. Search inside the Visual Studio application folder to find it.
  2. You need to add the folder containing swiftc.exe to the PATH environment variable to use the toolchain.
  3. You also need to add the folder containing the icu dlls to the PATH environment variable.

This can be achieved by entering the following into the command line.

path %PATH%;C:\Library\Developer\Toolchains\unknown-Asserts-development.xctoolchain\usr\bin
path %PATH%;C:\Library\icu63_1\bin64

Alternatively, to make these changes persistent go to the Windows environment variables edit dialog found in System Properties > Advanced > Environment Variables and edit the path variable to add the following two new items.


Note: After modifying the environment variables using this dialog, running applications must be restarted in order for changes to take effect.

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