migrate-dotnet9-to-dotnet10

SKILL.md

.NET 9 → .NET 10 Migration

Migrate a .NET 9 project or solution to .NET 10, systematically resolving all breaking changes. The outcome is a project targeting net10.0 that builds cleanly, passes tests, and accounts for every behavioral, source-incompatible, and binary-incompatible change introduced in the .NET 10 release.

When to Use

Upgrading TargetFramework from net9.0 to net10.0

Resolving build errors or new warnings after updating the .NET 10 SDK

Adapting to behavioral changes in .NET 10 runtime, ASP.NET Core 10, or EF Core 10

Updating CI/CD pipelines, Dockerfiles, or deployment scripts for .NET 10

Migrating from the community System.Linq.Async package to the built-in System.Linq.AsyncEnumerable

When Not to Use

The project already targets net10.0 and builds cleanly — migration is done

Upgrading from .NET 8 or earlier — use the migrate-dotnet8-to-dotnet9 skill first to reach net9.0, then return to this skill for the net9.0 → net10.0 migration

Migrating from .NET Framework — that is a separate, larger effort

Greenfield projects that start on .NET 10 (no migration needed)