What problem does it solve? Upgrading a project from .NET 9 to .NET 10 introduces dozens of breaking changes across the compiler, runtime, SDK, ASP.NET Core, EF Core, and cryptography APIs. This Skill provides a systematic, step-by-step workflow that updates the target framework, fixes build errors, addresses behavioral changes, and updates infrastructure so the migrated project builds cleanly and passes tests. ## Core Features & Use Cases - Guided six-step migration workflow: Assess the project, update the TargetFramework to net10.0, resolve source-incompatible changes, address behavioral changes, update Dockerfiles and CI/CD, then verify with builds and tests. - Technology-aware reference loading: Ten detailed reference documents cover C# 14 compiler changes, core libraries, SDK/MSBuild, ASP.NET Core, EF Core, cryptography, extensions/hosting, serialization/networking, WinForms/WPF, and containers/interop, loaded selectively based on project type. - Concrete fix patterns: Provides before/after code for SYSLIB0058-0062 obsoletions, the C# 14 field and extension keywords, span overload resolution, System.Linq.Async migration, Microsoft.OpenApi v2 changes, and Sqlite DateTimeOffset behavior. - Use Case: A team upgrades their ASP.NET Core Web API from net9.0 to net10.0 and hits build errors from the new field keyword, NU1510 warnings, and OpenApi namespace removals. The Skill walks them through each fix and flags behavioral changes like SIGTERM handling and configuration null binding before deployment. ## Quick Start Migrate my .NET 9 solution at ./src/MyApp.sln to .NET 10 and fix all resulting build errors and breaking changes.
