Who contributed to .NET on May 16, 2026?

7 developers shipped this update, including AlekseyTs, dibarbet, davidwengier, Copilot, max-charlamb, maraf, and PureWeen.

What were the notable .NET updates?

Merge Unions to main, Fix progress reporting to report done on dispose, and Fix single line script tag formatting.

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The Wire · Showcase

UNIONS LAND IN ROSLYN, RUNTIME TIGHTENS CDAC APIS

By RepoJournal · Filed 06:05 UTC on May 16, 2026 · About .NET

7 people shipped this

AlekseyTs @AlekseyTs 1 cited

dibarbet @dibarbet 1 cited

davidwengier @davidwengier 1 cited

Copilot @Copilot 1 cited

max-charlamb @max-charlamb 1 cited

maraf @maraf 1 cited

PureWeen @PureWeen 1 cited

C# unions just shipped to main in Roslyn [ref:3], while the runtime team hardened debugger contracts and cut WebAssembly build times.

The second wave of union implementation merged into Roslyn main [1] with full test coverage and championed proposal backing. This is the feature teams have been waiting for. In parallel, Roslyn squashed a critical LSP progress reporting bug [2] where project initialization would hang indefinitely because the API didn't auto-close work-done progress on dispose. Razor script tag formatting got fixed [3], cleaning up a long-standing indentation issue. Over in runtime, the team implemented four new DacDbi cDAC APIs [4] to simplify generic type context resolution, then fixed a gnarly bug where early debugger attachment would miss GC contract descriptors entirely [5]. WebAssembly builds got faster: incremental MSBuild targets now skip expensive Webcil conversion and BootJson generation on no-op rebuilds [6]. MAUI cleared house by removing the dormant ci-doctor workflow and pushing all agentic workflows to v0.72.1 [7], tightening automation across the board.

Action items

→ Test union syntax in Roslyn main - this is ready for production validation dotnet/roslyn [plan]
→ Pull WebAssembly incremental build targets upgrade to cut your rebuild times dotnet/runtime [plan]
→ Monitor cDAC sub-descriptor fix if you're using early debugger attachment dotnet/runtime [monitor]

References

[1] Merge Unions to main ↗ dotnet/roslyn
[2] Fix progress reporting to report done on dispose ↗ dotnet/roslyn
[3] Fix single line script tag formatting ↗ dotnet/roslyn
[4] Implement DacDbi cDAC APIs and simplify generic type context APIs ↗ dotnet/runtime
[5] [cDAC] Reparse pending sub-descriptors on Flush ↗ dotnet/runtime
[6] [browser] WebAssembly SDK targets more incremental ↗ dotnet/runtime
[7] Remove ci-doctor, upgrade all gh-aw workflows to v0.72.1 ↗ dotnet/maui

Quick answers

What shipped in .NET on May 16, 2026?: C# unions just shipped to main in Roslyn [ref:3], while the runtime team hardened debugger contracts and cut WebAssembly build times. In total, 29 commits and 19 pull requests landed.
Who contributed to .NET on May 16, 2026?: 7 developers shipped this update, including AlekseyTs, dibarbet, davidwengier, Copilot, max-charlamb, maraf, and PureWeen.
What were the notable .NET updates?: Merge Unions to main, Fix progress reporting to report done on dispose, and Fix single line script tag formatting.

RUNTIME FIXES KERBEROS FALLBACK ON UNIX, APPHOST CONVERTS TO C

The managed SPNEGO implementation now falls back to NTLM when Kerberos credentials go missing on Linux, closing a critical auth gap that broke enterprise deployments [ref:1].

dotnet 120 shipped 1-min read

@dotnet 1 day ago

MACIOS DOCS OVERHAUL SPANS 31 TYPES, ASPNETCORE VALIDATION MOVES TO SOURCE GENERATION

Rolf Bjarne shipped 31 types with proper XML documentation across macios while aspnetcore refactors validation classes out of the public API entirely.

dotnet 25 shipped 1-min read

@dotnet 2 days ago

SQLCLIENT KILLS PLATFORM-SPECIFIC BUILDS, ASPNETCORE HARDENS SIGNALR

SqlClient unified its Windows and Unix code paths without restructuring the NuGet package, collapsing build complexity across the entire SNI layer.

dotnet 97 shipped 2-min read

@dotnet 3 days ago

COMPLEX NUMBERS NOW IEEE 754 COMPLIANT, SKILLS EVALS GO VALLY-ONLY, UNSAFE EVOLVES

Complex<T> just shipped conformance to C23 Annex G special values, dotnet/skills completed its migration to the Vally eval harness, and the language is tightening unsafe semantics ahead of C# 13.

dotnet 141 shipped 2-min read

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