.NET Core - ArchWiki

# .NET Core

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.NET Core is a new FOSS software framework from Microsoft for C#, Visual Basic, and F#. It is designed to be cross-platform, modular and apt for modern applications, as opposed to its predecessor, the .NET Framework.

## Installation

If you only want to run .NET Core managed applications, install the dotnet-runtime package.

To build apps with .NET Core, install dotnet-sdk as well.

Microsoft recommends using Visual Studio Code , their Electron-based FOSS IDE, to build & debug .NET Core apps.

Tip: Add `~/.dotnet/tools` to `PATH`, otherwise dotnet tools will not work from shell.

### Install multiple versions

You can install multiple versions of the .NET Core SDK or runtime side by side by using the dotnet-install.sh script provided by the .NET Foundation. You can find the documentation of the script here.

For instance, this command would install the latest version found in the "current" channel in `/opt/dotnet`:

    # ./dotnet-install.sh --install-dir /opt/dotnet -channel Current -version latest

You may want to simulate the installation first by using the `-Dryrun` flag.

Once installed, you can verify the SDKs available:

    $ dotnet --list-sdks
    2.2.108 [/opt/dotnet/sdk]
    3.0.100 [/opt/dotnet/sdk]
    $ dotnet --version
    3.0.100

### Install PowerShell Core

You can install PowerShell Core as a "global" tool also [1] [2]

    # dotnet tool install --global PowerShell

to update to current version

    # dotnet tool update --global PowerShell

## Telemetry

Telemetry is enabled by default but can be disabled by setting environment variable `DOTNET_CLI_TELEMETRY_OPTOUT=1`.

## Troubleshooting

### It was not possible to find any compatible framework version

If you get the following error when you try to run a newly created project, you no longer need to set a `DOTNET_ROOT` variable as described in the solutions of various github issues. Arch's dotnet package (as of 3.1) installs it to the Microsoft recommended location of `/usr/share/dotnet`.

    $ dotnet run

    It was not possible to find any compatible framework version
    The framework 'Microsoft.AspNetCore.App', version '3.1.0' was not found.
      - No frameworks were found.

    You can resolve the problem by installing the specified framework and/or SDK.

    The specified framework can be found at:
      - https://aka.ms/dotnet-core-applaunch?framework=Microsoft.AspNetCore.App&framework_version=3.1.0&arch=x64&rid=arch-x64

This is caused because the runtime is shipped as a separate package in Arch. You just need to make sure you have the aspnet-runtime package installed as well.

### "the required library libhostfxr.so could not be found" error

Some of the dotnet SDK tools (for example libman, dotnet-watch etc.) may expect you to have the environment variable `DOTNET_ROOT` pre-configured. If it's not, an error like this one could be observed: [3]

    A fatal error occurred, the required library libhostfxr.so could not be found.
    If this is a self-contained application, that library should exist in [/home/my_user/.dotnet/tools/.store/microsoft.web.librarymanager.cli/1.0.172/microsoft.web.librarymanager.cli/1.0.172/tools/netcoreapp2.1/any/].
    If this is a framework-dependent application, install the runtime in the default location [/usr/share/dotnet] or use the DOTNET_ROOT environment variable to specify the runtime location.

The workaround is to manually export `DOTNET_ROOT` in your shell:

    ~/.bashrc

    export DOTNET_ROOT=/opt/dotnet

### SDK specified could not be found

This is believed to caused by a conflict between the Mono and MSBuild SDK libs and the dotnet core ones. To fix this export the path manually in your shell (replacing the version number as necessary) e.g:

    ~/.bashrc

    export MSBuildSDKsPath=$( echo /usr/share/dotnet/sdk/3.*/Sdks );

## See also

- .NET Core homepage
- The .NET Foundation
- .NET API Browser

Category:

- Frameworks