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migrate-dotnet8-to-dotnet9

85 / 100 · Low risk

Fine to try.

By dotnet/skills (GitHub) · other · 5,870 stars · scanned at commit 96c3d68

Migrate a .NET 8 project to .NET 9 and resolve all breaking changes. USE FOR: upgrading TargetFramework from net8.0 to net9.0, fixing build errors after updating the .NET 9 SDK, resolving behavioral changes in .NET 9 / C# 13 / ASP.NET Core 9 / EF Core 9, replacing BinaryFormatter (now always throws), resolving SYSLIB0054-SYSLIB0057, adapting to params span overload resolution, fixing C# 13 compiler changes, updating HttpClientFactory for SocketsHttpHandler, and resolving EF Core 9 migration/Cos…

Works with any agent that supports SKILL.md skills.

What this skill can do

Install

Paste this into your terminal. It downloads exactly the version we scanned, not whatever is newest.

if [ -e ~/.agents/skills/'migrate-dotnet8-to-dotnet9' ] || [ -L ~/.agents/skills/'migrate-dotnet8-to-dotnet9' ]; then echo 'A skill folder named migrate-dotnet8-to-dotnet9 already exists — not replacing it' >&2; false; else d=$(mktemp -d) && git clone --quiet --filter=blob:none --no-checkout 'https://github.com/dotnet/skills' "$d" && git -C "$d" checkout --quiet '96c3d68dad2855e3ab5178aa1a262789d86a1466' -- 'plugins/dotnet-upgrade/skills/migrate-dotnet8-to-dotnet9' && mkdir -p ~/.agents/skills && cp -R "$d"/'plugins/dotnet-upgrade/skills/migrate-dotnet8-to-dotnet9' ~/.agents/skills/'migrate-dotnet8-to-dotnet9' && rm -rf "$d"; fi

Codex reads ~/.agents/skills directly. For Claude Code, Cursor, Copilot, Gemini CLI, Antigravity or OpenCode, also link it. For Claude Code: ln -s ~/.agents/skills/'migrate-dotnet8-to-dotnet9' ~/.claude/skills/'migrate-dotnet8-to-dotnet9' (other agents: ~/.cursor/skills, ~/.copilot/skills, ~/.gemini/skills, ~/.gemini/config/skills, ~/.config/opencode/skills). Or install through the finder skill, which does both.

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