Modernization Phase 1.3: vcpkg baseline 2026.06.24 + dependency wave [iosbuild]

[ptesavol]

Phase 1.3 of the modernization: the dependency update wave — the phase the plan flagged as highest-risk. Three commits: baseline bump + overlay reset, SDK adaptation, iOS restoration + docs.

The baseline

vcpkg submodule: 2024-09 pin → tag 2026.06.24, with builtin-baseline now pinned in vcpkg.json (enables per-port overrides; the merge script preserves the key; and since CI cache keys hash vcpkg.json, baseline bumps bust caches automatically — the planned cache-key/submodule-SHA work became unnecessary).

Resulting versions: protobuf 6.33.4 (from 25.1!), folly 2026.02.23, boost 1.91, openssl 3.6.3, libdatachannel 0.24.5, fmt 12.2, secp256k1 0.7.1.

Overlay diet (the headline)

All five old overlay directories deleted (folly/usrsctp/libdatachannel/magic-enum/fmt), along with Phase 1.2's CMake-4 stopgaps (CMAKE_POLICY_VERSION_MINIMUM, VCPKG_OSX_SYSROOT) — the new vcpkg handles CMake 4 itself. Three minimal overlays returned, strictly evidence-driven, each with a JUSTIFICATION.md:

Overlay	Content	Why
folly	1 patch + 1 option	Missing <exception> include (libc++ 22 hard error); FOLLY_NO_EXCEPTION_TRACER=ON — see below
secp256k1	1 option	Recovery module is upstream-default-off; SigningUtils needs it
usrsctp	2 patches	The pre-2026 iOS patches (no net/route.h/ifaddrs.h in the iPhoneOS SDK) — verified still required

The folly exception-tracer find deserves a mention: after the bump, 18 tests aborted — every single one exercising an error path. Bisected with minimal repros down to: std::current_exception() returning null inside catch blocks, process-wide. Cause: folly 2026's exception tracer interposes __cxa_throw and now activates on macOS (the 2024 tracer was glibc-only and compiled to empty objects on libc++), breaking exception introspection for everyone. One configure option kills it; the SDK never used the tracer.

SDK adaptations

• Protobuf 25→33: all checked-in generated code regenerated with protoc 33.4 (the bulk of the diff); the codegen plugin ported to the absl::string_view descriptor API; proto.sh scripts now detect the protoc triplet dir (was hardcoded arm64-osx) and drop the removed --experimental_allow_proto3_optional flag; protobuf::libprotoc removed from library targets (only the host plugin needs it; the new port doesn't export it for cross triplets).
• folly API: seven scheduleOn(exec) sites → co_withExecutor(exec, task) (2026 deprecation, fatal under warnings-as-errors lint).
• magic-enum 0.9.8 header move (magic_enum/magic_enum.hpp); libdatachannel 0.24 target rename; secp256k1_precomputed archive no longer exists (merged into main lib) → optional; RpcCommunicatorTest compares message fields instead of DebugString() output (6.33 prefixes a goo.gle/debugproto marker — the format was never stable); -fpermissive removed from proto-rpc (GCC-only, plan item).

Verification

Gate	Result
macOS full build (clean, all deps at new baseline)	✅
Tests	✅ 307/307
Full lint (clangd 22 + clang-format 22)	✅
iOS cross-build + XCFramework (platform=iOS, minos=13.0, no post-deployment-target runtime symbols)	✅
Linux + iOS CI	this PR (title carries iosbuild)
Regenerated proto diff	for your review — mechanical protoc output

Follow-ups

• fmt overlay from 1.2 is gone as predicted; MODERNIZATION.md updated; README documents the baseline-bump procedure (including the overlay-revisit rule).
• Part 1 remaining: Phase 1.4 (iOS libc++ arrangement + deployment target + ios.toolchain refresh), 1.5 (lint remainder: clangd-tidy submodule + suppression triage), 1.6 (CI/docs closeout). Then Part 2: modules.

🤖 Generated with Claude Code

[ptesavol]

Final CI state — all green ✅

Check	Result
validate: macos-latest (LLVM 22, new baseline)	✅ install + lint + test
validate: ubuntu-latest (clang-22 + libc++)	✅ install + lint + test
validate: linux-arm64-runner (clang-22 + libc++)	✅ install + lint + test
validate iOS (XCFramework at the new baseline)	✅
Local	✅ build, 307/307 tests, lint, iOS artifact verified

One CI-only fix landed after opening: the new baseline pulls libunwind on Linux, whose port needs autotools from the system (autoconf autoconf-archive automake libtool added to install-prerequisities.sh).

This is the first time the complete matrix is green in a single run during the modernization — old toolchain fully retired, dependencies current, three documented overlays remaining (down from five opaque ones).

Ready for review. The regenerated protobuf sources are the bulk of the diff; the interesting commits are the overlay justifications and the folly exception-tracer analysis.

🤖 Generated with Claude Code