[Repo Assist] Monthly Activity 2026-04

[github-actions]

🤖 Repo Assist here — I'm an automated AI assistant for this repository.

Activity for April 2026

Suggested Actions for Maintainer

Comprehensive list of all pending actions requiring maintainer attention (excludes items already actioned and checked off).

• Review PR #19472: fix for #12796 — empty array support in custom attributes — has merge conflicts — Review
• Close issue #5418: confirmed fixed (PR Fix wrong warning 20 range in sequential expressions (#5735) #19504 merged 2026-04-11), existing test coverage in WarnExpressionTests.fs — View comment
• Close issue #13512: confirmed fixed (PR Fix completion inconsistently filtering obsolete fields and events (#13512) #19506 merged 2026-04-11), comprehensive test coverage in CompletionTests.fs — View comment
• Check comment on #13099: Task CE optimizer correctness bug — (someFunctionWithReturnType()).End silently optimized away in Release mode — View
• Check comment on #16982: delegate keyword breaks semantic highlighting — reproduced via FCS, AI-thinks-windows-only removed — View
• Check comment on #18841: let _ = &s still raises FS0421 — AI-thinks-issue-fixed was incorrectly applied then removed — View
• Check comments on #16034, #16464: confirmed still present, Repo Assist provided repro details

Additional observations for maintainer's attention

• Issue #13099: High-impact optimizer correctness bug — (someFunctionWithReturnType()).End where .End is a unit property causes the function call to be optimized away in Release mode, silently swallowing the side effect (including failwith). Confirmed with F# 11.0 on .NET 10.
• Issue #15627: async { } |> Async.RunSynchronously at module level before [<EntryPoint>] still deadlocks. Confirmed on F# 11.0 / .NET 10.
• Issue #12303: AddBackticksToIdentifierIfNeeded "not" still returns ``not`` (incorrect — not is a stdlib function, not a keyword). Also, params and parallel are NOT getting backticks when they should.
• Issue #12379: Recursive type with Zero constraint still fails to compile. dsyme confirmed this is a phasing bug in the type checker.
• Issue #16292: Debug-only codegen bug — SRTP with mutable struct enumerator causes infinite loop in Debug builds. Release works correctly. Verified: Debug build hangs (timeout after 5s), Release prints expected output. The struct enumerator's MoveNext() mutation is lost due to defensive copying.

Future Work for Repo Assist

• Task 1: Cursor at 0 (full scan complete) — monitoring for new activity on pre-2024 bugs
• Task 3: woc=18119 — all windows-only issues reassessed; monitoring for newly labeled issues
• Task 2: rtc=14566 — monitoring for newly labeled AI-thinks-issue-fixed issues

Run History

2026-04-29 01:16 UTC — Run

• 🔍 Scanned for pre-2024 bugs with activity since 2026-04-28: none found
• 🔍 Checked AI-thinks-windows-only issues: none above cursor (woc=18119)
• 🔍 Checked AI-thinks-issue-fixed issues: Wrong expression is ignored warning range #5418 and Completion is available for some obsolete members only #13512 already verified with test coverage in prior runs (rtc=14566)
• 📊 No new actions — all pending items unchanged since last run

2026-04-28 01:15 UTC — Run

• 🔍 Scanned for pre-2024 bugs with activity since 2026-04-27: none found
• 🔍 Checked AI-thinks-windows-only issues: none above cursor (woc=18119)
• 🔍 Checked AI-thinks-issue-fixed issues: Wrong expression is ignored warning range #5418 and Completion is available for some obsolete members only #13512 already verified with test coverage in prior runs (rtc=14566)
• 📊 No new actions — all pending items unchanged since last run

2026-04-27 01:12 UTC — Run

• 🔍 Scanned for pre-2024 bugs with activity since 2026-04-26: none found
• 🔍 Checked AI-thinks-windows-only issues: none above cursor (woc=18119)
• 🔍 Checked AI-thinks-issue-fixed issues: Wrong expression is ignored warning range #5418 and Completion is available for some obsolete members only #13512 already verified with test coverage in prior runs (rtc=14566)
• 📊 No new actions — all pending items unchanged since last run

2026-04-26 01:12 UTC — Run

• 🔍 Scanned for pre-2024 bugs with activity since 2026-04-25: none found
• 🔍 Checked AI-thinks-windows-only issues: none above cursor (woc=18119)
• 🔍 Checked AI-thinks-issue-fixed issues: Wrong expression is ignored warning range #5418 and Completion is available for some obsolete members only #13512 already verified with test coverage in prior runs (rtc=14566)
• 📊 No new actions — all pending items unchanged since last run

2026-04-24 01:10 UTC — Run

• 🔍 Scanned for pre-2024 bugs with activity since 2026-04-23: none found
• 🔍 Checked AI-thinks-windows-only issues: none above cursor (woc=18119)
• 🔍 Checked AI-thinks-issue-fixed issues: Wrong expression is ignored warning range #5418 and Completion is available for some obsolete members only #13512 already verified with test coverage in prior runs
• 📊 No new actions — all pending items unchanged since last run

2026-04-21 12:52 UTC — Run

• 🔍 Scanned 31 pre-2024 bugs (Telemetry exception in VS #16083–Can't use addition (substruction) multiple times in member for constrained to INumber<> generic  #16464): all confirmed still present on F# 11.0 (FSI 15.2.101.0, commit 92fd65a)
• 🔍 Verified Incorrect codegen for Debug build with srtp and mutable struct #16292 (Debug codegen infinite loop), Parenthesized/double unit literal () → (()) required in certain scenarios #16254 (unit literal FS0768), Cannot supply typeof<> to attribute constructor #16344 (typeof in attribute), Unresolved name error in 'inherit' member reported multiple times #16432 (3x duplicate FS0039), Don't warn FS3559 when obj is inferred if the obj is expected there #16454/FS3559 triggers on query expressions #16455 (FS3559 false positives), TryFinallyAsync implementation ignores potential exceptions in TryFinally #16189 (TryFinally exception loss)
• 📊 Cursor completed full pre-2024 range → reset to 0; PR Add regression test: #3783, Mutually recursive computation expression NullReferenceException #19613 merged, Mutually recursive computation expression raises NullReferenceException under some conditions #3783 closed

2026-04-21 01:08 UTC — Run

• 🔍 Scanned ~40 pre-2024 bugs (Support 'protected abstract' #12281–Strange order dependency of members with cancellable tasks #15940): all confirmed still present
• 💬 Commented on #13099: Verified optimizer correctness bug — (someFunctionWithReturnType()).End silently optimized away in Release mode, Debug works correctly
• 📊 Updated cursor from 11770 → 15940

2026-04-20 12:54 UTC — Run

• 🔍 Scanned ~20 pre-2024 bugs (Returning a voidptr option throws at runtime #9994–FsiEvaluationSession cant find Fsharp.Core when hosted in another process. #11770): all confirmed still present
• 💬 Commented on #11626: verified still present via FCS UnusedOpens API
• 📊 Updated cursor from 9838 → 11770

Earlier runs (2026-04-01 through 2026-04-20)

• Investigated pre-2024 bugs, reassessed windows-only issues, created regression tests
• PRs merged: Add regression test: #10043, backtick should not report unexpected keyword #19476, Add regression test: #16154, task CE with IQueryable filters no longer throws VerificationException #19530, Fix #12386, SRTP trait call correct overload resolution in multi-submit FSI scenario #19471, Add regression test: #13114, SynPat.Record and QuoteExpr traversal #19468, Add regression test: #1255, identifiers with @ produce correct codegen #19579, Add regression test: #4473, extern function parameters not flagged as unused #19580, Add regression test: #14566, false positive unused value warnings in query CEs #19581, Add regression test: #3783, Mutually recursive computation expression NullReferenceException #19613

Generated by 🌈 Repo Assist, see workflow run. Learn more.

To install this agentic workflow, run

gh aw add githubnext/agentics/workflows/repo-assist.md@7c7feb61a52b662eb2089aa2945588b7a200d404