Building ASP.NET Core from source allows you tweak and customize ASP.NET Core, and to contribute your improvements back to the project.
:warning: We are currently in the middle of restructing our source code. These instructions will likely change rapidly during November and December 2018.
See https://github.com/aspnet/AspNetCore/labels/area-infrastructure for known issues and to track ongoing work.
Building ASP.NET Core on Windows requires:
Building ASP.NET Core on macOS or Linux requires:
ASP.NET Core uses git submodules to include source from a few other projects.
For a new copy of the project, run:
git clone --recursive https://github.com/aspnet/AspNetCore
To update an existing copy, run:
git submodule update --init --recursive
Before opening our .sln files in Visual Studio or VS Code, you need to perform the following actions.
Executing the following on command-line:
.\build.cmd /p:SkipTests=true /p:_ProjectsOnly=true
This will download required tools and build the entire repository once. At that point, you should be able to open .sln files to work on the projects you care about.
Use the startvs.cmd script to open Visual Studio .sln files. This script first sets required environment variables.
:bulb: Pro tip: you will also want to run this command after pulling large sets of changes. Visual Studio will only build projects in a solution file, and makes a best effort to use other files on disk. If you pull many changes, the files on disk may be stale and will need to re-build.
We don't have a single .sln file for all of ASP.NET Core because Visual Studio doesn't currently handle projects of this scale. Instead, we have many .sln files which include a sub-set of projects. These principles guide how we create and manage .slns:
:bulb: Pro tip:
dotnet new slnanddotnet slnare one of the easiest ways to create and modify solutions.
Opening solution files may produce an error code NU1105 with a message such
Unable to find project information for 'C:\src\AspNetCore\src\Hosting\Abstractions\src\Microsoft.AspNetCore.Hosting.Abstractions.csproj'. Inside Visual Studio, this may be because the project is unloaded or not part of current solution. Otherwise the project file may be invalid or missing targets required for restore.
This is a known issue in NuGet (https://github.com/NuGet/Home/issues/5820) and we are working with them for a solution. See also https://github.com/aspnet/AspNetCore/issues/4183 to track progress on this.
The workaround for now is to add all projects to the solution.
dotnet sln add C:\src\AspNetCore\src\Hosting\Abstractions\src\Microsoft.AspNetCore.Hosting.Abstractions.csproj
For VS Code and Visual Studio and dotnet commands to work correctly, you must place the following location in your PATH.
Use the following commands to update the PATH variable in a command line window.
Windows (Command Prompt)
set PATH=%USERPROFILE%\.dotnet\x64;%PATH%
Windows (Powershell)
$env:PATH="$env:USERPROFILE\.dotnet\x64;$env:PATH"
Linux/macOS:
export PATH="$HOME/.dotnet:$PATH"
On Windows, we recommend using the startvs.cmd command to launch Visual Studio.
You can also build the entire project on command line with the build.cmd/.sh scripts.
On Windows:
.\build.cmd
On macOS/Linux:
./build.sh
This repository is large. Look for build.cmd/.sh scripts in subfolders. These scripts can be used to invoke build and test on a smaller set of projects.
We'll be adding more. See https://github.com/aspnet/AspNetCore/issues/4247.
Additional properties can be added as an argument in the form /property:$name=$value, or /p:$name=$value for short. For example:
.\build.cmd /p:Configuration=Release
Common properties include:
| Property | Description |
|---|---|
| BuildNumberSuffix | (string). A specific build number, typically from a CI counter, which is appended to the pre-release label. |
| Configuration | Debug or Release. Default = Debug. |
| SkipTests | true or false. When true, builds without running tests. |
| NoBuild | true or false. Runs tests without rebuilding. |
After building ASP.NET Core from source, you will need to install and use your local version of ASP.NET Core.
artifacts/{Debug, Release}/installers/ for your platform.Add a NuGet.Config to your project directory with the following content:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<packageSources>
<clear />
<add key="MyBuildOfAspNetCore" value="C:\src\aspnet\AspNetCore\artifacts\build\" />
<add key="NuGet.org" value="https://api.nuget.org/v3/index.json" />
</packageSources>
</configuration>
NOTE: This NuGet.Config should be with your application unless you want nightly packages to potentially start being restored for other apps on the machine.
Update the versions on PackageReference items in your .csproj project file to point to the version from your local build.
<ItemGroup>
<PackageReference Include="Microsoft.AspNetCore.SpaServices" Version="3.0.0-preview-0" />
</ItemGroup>
Some features, such as new target frameworks, may require prerelease tooling builds for Visual Studio. These are available in the Visual Studio Preview.