0.23.3: the stub of libSystem only when the link has no SDK

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ on:
         default: ""
 env:
   MCPP_SOURCE_REF: ${{ github.event.inputs.mcpp_ref || vars.MCPP_SOURCE_REF }}
-  MCPP_VERSION: 2026.11.9.1
+  MCPP_VERSION: 2026.11.14.1
   XLINGS_VERSION: v2026.10.26.1
   # The mtest engine the runs are reported with: the conformance suite's cases
   # (tools/run-conformance.sh with MTEST set) and `mcpp test`'s store (target/mtest).
@@ -255,6 +255,23 @@ jobs:
           test "$missing" -eq 0
           done
 
+      # AND WITH THE TARGET REQUESTED, which is a different link on this
+      # machine. The steps above build natively, where no target is requested
+      # and the stub of `libSystem` was never supplied; `--target aarch64-macos`
+      # here is the build in which it was, ahead of the SDK the link carries
+      # (0.23.3, `undefined symbol: strlen`). The SDK must answer, so this
+      # needs an mcpp that states it (`MCPP_TARGET_SDK`, 2026.11.14.1+).
+      - name: This package's own tests, the target requested
+        run: |
+          set -euo pipefail
+          mcpp test --target aarch64-macos 2>&1 | tee tests-target.log
+          missing=0
+          for f in tests/*.cpp; do
+            name="$(basename "$f" .cpp)"
+            grep -q "^$name \.\.\. ok" tests-target.log || { echo "did not run or did not pass: $name (--target)" >&2; missing=1; }
+          done
+          test "$missing" -eq 0
+
       - name: This package's test runs, kept for the report
         if: always()
         run: |
@@ -460,8 +477,8 @@ jobs:
       - name: The failing cases, explained
         if: failure()
         run: |
-          [ -n "${MTEST:-}" ] && [ -d .spec/conformance/.mtest ] || exit 0
-          ( cd .spec/conformance && "$MTEST" explain ) || true
+          [ -n "${MTEST:-}" ] && [ -d .spec/tests/cts/.mtest ] || exit 0
+          ( cd .spec/tests/cts && "$MTEST" explain ) || true
 
       # THE RUNS OF THIS JOB, REPORTED: the conformance suite's (one case per
       # interface, its observations within it) and `mcpp test`'s (one case per
@@ -473,7 +490,7 @@ jobs:
           [ -n "${MTEST:-}" ] || { echo "no mtest engine in this job"; exit 0; }
           store="$(cygpath -u "$RUNNER_TEMP" 2> /dev/null || printf '%s' "$RUNNER_TEMP")/mtest-store"
           mkdir -p "$store"; here="$PWD"
-          for from in "$here/.spec/conformance/.mtest" "$RUNNER_TEMP/mcpp-test-runs"; do
+          for from in "$here/.spec/tests/cts/.mtest" "$RUNNER_TEMP/mcpp-test-runs"; do
             if [ -f "$from/index.ndjson" ]; then ( cd "$store" && "$MTEST" store import --from "$from" ); fi
           done
           [ -f "$store/.mtest/index.ndjson" ] || { echo "no run was kept"; exit 0; }

README.md

@@ -8,7 +8,7 @@ written on the kernel's own calls.
 openkal = "0.25.0"
 
 [target.'cfg(os = "macos")'.dependencies]
-openkal-macos = "0.23.2"
+openkal-macos = "0.23.3"
 ```
 
 Its purpose is as much to test the specification as to be used. A specification
@@ -183,6 +183,17 @@ same image parses as fast on Linux arm64. Since 0.17.1 it is the same kernel ide
 this system's library keeps for each thread (`pthread_threadid_np`, a name no C
 library in this ecosystem defines).
 
+## What 0.23.3 corrects
+
+**The stub of `libSystem` is supplied only when the link has no SDK.** A build
+for this system with a target requested (`mcpp build --target aarch64-macos`) on
+a Mac put `port/` on the link, ahead of the SDK that mcpp has named there since
+2026.8.25.2, and the three names of the stub shadowed the SDK's complete library
+(`undefined symbol: strlen`). The build program now asks mcpp's
+`MCPP_TARGET_SDK` (2026.11.14.1+), the SDK the link names, and supplies the stub
+when a target was requested and that is empty: a cross link from another host.
+An older mcpp sets no such variable, and the condition is then the previous one.
+
 ## What 0.23.2 corrects
 
 The manifest declares `openkal = "^0.25.0"`. An implementation written against a

build.mcpp

@@ -54,42 +54,37 @@ import std;
 // links against it just as well and names the same library.
 
 int main() {
-    // THE CONDITION IS NOT "WHICH MACHINE", AND THE FIRST TWO ATTEMPTS AT
-    // IT BOTH WERE.
+    // THE QUESTION IS WHETHER THE SYSTEM'S OWN STUB IS ON THE LINK, AND mcpp
+    // ANSWERS IT: `MCPP_TARGET_SDK` names the SDK the link carries with
+    // `-isysroot`, and is empty when the link names none (mcpp 2026.11.14.1+).
+    // Ours is supplied exactly when a target was requested and no SDK is on
+    // the link — a cross link to this system from another host.
     //
-    // Attempt one supplied the stub always, and on this system it SHADOWED the
-    // vendor's — which lists every name rather than three (see above).
-    // Attempt two asked whether the host was this system, and that failed the
-    // other way: `mcpp build --target aarch64-macos` ON a Mac is a build whose
-    // target side comes from the graph, and the build tool deliberately keeps
-    // this machine's SDK off such a link. The vendor's stub was then not there
-    // either, and neither was ours:
+    // THE THREE ATTEMPTS BEFORE THIS ONE EACH ASKED A NEIGHBOURING QUESTION.
+    //
+    // Always: the stub shadowed the vendor's on this system (above).
+    // The host: `mcpp build --target aarch64-macos` ON a Mac then had no
+    // `libSystem` at all, because mcpp kept the SDK off such a link for one
+    // day (2026-08-24):
     //
     //     ld64.lld: error: library not found for -lSystem
-    //     ld64.lld: error: undefined symbol: clock_gettime_nsec_np
-    //     ld64.lld: error: undefined symbol: pthread_create_from_mach_thread
     //
-    // The fact that decides it is whether the build was POINTED AT A TARGET.
-    // When it was, the tool supplies no system of its own and this package is
-    // the only thing that can name one. When it was not — a native build, which
-    // is what this package's own conformance suite does — the SDK is on the
-    // link and is the complete answer.
-    // `MCPP_TARGET_REQUESTED` AND NOT `MCPP_TARGET`. The second is filled in
-    // with the host when nobody named a target, so it is never empty and the
-    // test was always true — which put this stub on a NATIVE link, where the
-    // SDK's complete one was already there and ours shadowed it:
+    // A requested target (`MCPP_TARGET_REQUESTED`, which is empty on a native
+    // build, unlike `MCPP_TARGET`): right for that day's mcpp, and wrong from
+    // the next, which kept `-isysroot` on every link of this system's format on
+    // a Mac (2026.8.25.2). The stub was put ahead of the SDK's and shadowed it
+    // again, on a Mac with `--target` only — a case no build here exercised
+    // until mcpp's canary `cxx aarch64-macos test` (2026-11-14):
     //
-    //     ld64.lld: error: undefined symbol: wcslen / strtoul / __error
+    //     ld64.lld: error: undefined symbol: strlen / memcpy / pthread_create
     //
-    // The first is the value unfilled: empty exactly when this is an ordinary
-    // native build. See mcpp's `build_program.cppm` for why the two are
-    // different questions even when the triples are equal.
+    // Each was a proxy for the fact; the fact is the tool's to state.
     //
-    // An mcpp too old to set it leaves it empty, and that is the right answer
-    // for such a build tool: it has no graph-supplied target side, so the
-    // system is always on the link.
+    // An mcpp too old to set `MCPP_TARGET_SDK` leaves it empty, and the
+    // condition is then the previous one: such a build behaves as it did.
     const char* requested = std::getenv("MCPP_TARGET_REQUESTED");
-    if (requested && *requested)
+    const char* sdk = std::getenv("MCPP_TARGET_SDK");
+    if (requested && *requested && !(sdk && *sdk))
         mcpp::link_search("port");
     mcpp::rerun_if_changed("port/libSystem.tbd");
     return 0;

mcpp.toml

@@ -1,7 +1,7 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-macos"
-version     = "0.23.2"
+version     = "0.23.3"
 description = "An implementation of openkal for macOS, written on the kernel's own calls. Its purpose is as much to test the specification as to be used."
 license     = "Apache-2.0"