.NET

.NET 9

Warning .NET 9 is a prerelease version.

• How to use a prerelease version
• Release notes
• Known issues

.NET 8

• Release notes
• Known issues

.NET 7

• Release notes
• Known issues

.NET 6

• Release notes
• Known issues
• Breaking changes

How to run on Device/Simulator from the command line

The general process is documented here:

https://docs.microsoft.com/en-us/dotnet/maui/ios/cli

but does not include running on an attached device.

To do that, include -p:RuntimeIdentifier=ios-arm64, along with the other parameters.

dotnet build -t:run -f:net6.0-ios -p:RuntimeIdentifier=ios-arm64 -p:_DeviceName=MY_SPECIFIC_UUID

with MY_SPECIFIC_UUID found as described here but for your device.

Note that this does not work from Windows, only from a Mac.

Strange "network" failures in local builds

Occasionally builds can fail in builds package-download with no useful information like this:

Making all in builds
cd package-download && /Users/donblas/Programming/xamarin-macios/builds/downloads/dotnet-sdk-7.0.100-rc.2.22458.3/dotnet \
                build \
                download-packages.proj \
                /t:WriteBundledNETCorePlatformsPackageVersion \
                /p:WriteFilePath=/Users/donblas/Programming/xamarin-macios/builds/BundledNETCorePlatformsPackageVersion.txt \
                /p:PackageRuntimeIdentifiers="ios-arm ios-arm64 iossimulator-x86 iossimulator-x64 iossimulator-arm64 tvos-arm64 tvossimulator-x64 tvossimulator-arm64 maccatalyst-x64 maccatalyst-arm64 osx-x64 osx-arm64" \
                /p:PackageRuntimeIdentifiersCoreCLR="osx-x64 osx-arm64" \
                /p:CustomDotNetVersion="7.0.0-rc.2.22460.1" \
                /p:DotNetManifestVersionBand="7.0.100" \
                /p:ToolChainManifestVersionBand="7.0.100" \
                /bl \
                --verbosity detailed
MSBuild version 17.4.0-preview-22451-06+2db11c256 for .NET
/Users/donblas/Programming/xamarin-macios/builds/downloads/dotnet-sdk-7.0.100-rc.2.22458.3/sdk/7.0.100-rc.2.22458.3/MSBuild.dll --property:WriteFilePath=/Users/donblas/Programming/xamarin-macios/builds/BundledNETCorePlatformsPackageVersion.txt --property:PackageRuntimeIdentifiers=ios-arm ios-arm64 iossimulator-x86 iossimulator-x64 iossimulator-arm64 tvos-arm64 tvossimulator-x64 tvossimulator-arm64 maccatalyst-x64 maccatalyst-arm64 osx-x64 osx-arm64 --property:PackageRuntimeIdentifiersCoreCLR=osx-x64 osx-arm64 --property:CustomDotNetVersion=7.0.0-rc.2.22460.1 --property:DotNetManifestVersionBand=7.0.100 --property:ToolChainManifestVersionBand=7.0.100 -consoleloggerparameters:Summary -distributedlogger:Microsoft.DotNet.Tools.MSBuild.MSBuildLogger,/Users/donblas/Programming/xamarin-macios/builds/downloads/dotnet-sdk-7.0.100-rc.2.22458.3/sdk/7.0.100-rc.2.22458.3/dotnet.dll*Microsoft.DotNet.Tools.MSBuild.MSBuildForwardingLogger,/Users/donblas/Programming/xamarin-macios/builds/downloads/dotnet-sdk-7.0.100-rc.2.22458.3/sdk/7.0.100-rc.2.22458.3/dotnet.dll -maxcpucount -restore -verbosity:m -verbosity:detailed /bl /t:WriteBundledNETCorePlatformsPackageVersion download-packages.proj
Build started 9/15/2022 8:53:13 AM.
     0>Process = "/Users/donblas/Programming/xamarin-macios/builds/downloads/dotnet-sdk-7.0.100-rc.2.22458.3/dotnet"
       MSBuild executable path = "/Users/donblas/Programming/xamarin-macios/builds/downloads/dotnet-sdk-7.0.100-rc.2.22458.3/sdk/7.0.100-rc.2.22458.3/MSBuild.dll"
       Command line arguments = "/Users/donblas/Programming/xamarin-macios/builds/downloads/dotnet-sdk-7.0.100-rc.2.22458.3/sdk/7.0.100-rc.2.22458.3/MSBuild.dll -maxcpucount -verbosity:m -restore -consoleloggerparameters:Summary --property:WriteFilePath=/Users/donblas/Programming/xamarin-macios/builds/BundledNETCorePlatformsPackageVersion.txt --property:PackageRuntimeIdentifiers=ios-arm ios-arm64 iossimulator-x86 iossimulator-x64 iossimulator-arm64 tvos-arm64 tvossimulator-x64 tvossimulator-arm64 maccatalyst-x64 maccatalyst-arm64 osx-x64 osx-arm64 --property:PackageRuntimeIdentifiersCoreCLR=osx-x64 osx-arm64 --property:CustomDotNetVersion=7.0.0-rc.2.22460.1 --property:DotNetManifestVersionBand=7.0.100 --property:ToolChainManifestVersionBand=7.0.100 -verbosity:detailed download-packages.proj /t:WriteBundledNETCorePlatformsPackageVersion /bl -distributedlogger:Microsoft.DotNet.Tools.MSBuild.MSBuildLogger,/Users/donblas/Programming/xamarin-macios/builds/downloads/dotnet-sdk-7.0.100-rc.2.22458.3/sdk/7.0.100-rc.2.22458.3/dotnet.dll*Microsoft.DotNet.Tools.MSBuild.MSBuildForwardingLogger,/Users/donblas/Programming/xamarin-macios/builds/downloads/dotnet-sdk-7.0.100-rc.2.22458.3/sdk/7.0.100-rc.2.22458.3/dotnet.dll"
       Current directory = "/Users/donblas/Programming/xamarin-macios/builds/package-download"
       MSBuild version = "17.4.0-preview-22451-06+2db11c256"

Build FAILED.
    0 Warning(s)
    0 Error(s)

This is not a network issue, it turns out the C# compile server is broken in memory and causing chaos.

To resolve it, search for instances with:

• ps aux|grep vbcs -i
• ps aux|grep msbuild -i

and kill -9 the PID (the first number on any matching non-grep lines).