2026.9.26.1: paths in UTF-8, a C standard per package, a graph link without the host, and the level that was declared

.agents/docs/2026-09-25-issue-690-workspace-build-inheritance-consistency.md

@@ -67,6 +67,8 @@ The decisions below are derived from these rules. Each rule names its source in
 | `dialect_cxxflags`, `c_standard`, `linkage`, `target`, `cxx_runtime`, `dependency_linkage`, `macos_deployment_target` | root manifest only | graph-wide | n/a | consistent |
 | `ios_deployment_target` | parsed and inherited | **refused** | n/a | **F3** |
 
+**Correction (2026-09-26, mcpp#695).** The row above classifies `c_standard` as read from the root manifest only and calls that consistent. For C the classification is wrong. A C translation unit produces no BMI, so nothing requires one C standard across the graph, and the package's own cache key and fingerprint already recorded the value as the package's. The root's value reached every dependency's C units through the file-level `$cflags` line, and a dependency's own declaration was not applied. From mcpp 2026.9.26.1 each package's C units compile at that package's own standard (docs/04, "`c_standard` applies to the package that declares it"); the plan is `2026-09-25-issues-693-696-triage-and-repair-plan.md`.
+
 ### 3.2 Inheritance placement: F1, F2, F8
 
 **F1 (measured): `defines` are lost for a member reached as a `path` dependency.** On the dependency branch, `fold_build_defines_into_flags(dep_manifest->buildConfig)` (`src/build/prepare.cppm:8235`) folds and clears `defines`. `makePackageRoot` (`prepare.cppm:6709`) then calls `inherit_workspace_build`, which prepends the workspace `defines` to the folded manifest. It copies `cflags`/`cxxflags` into `privateBuild` without folding again. The failure is silent unless the source guards the macro. Workspace-wide defines are typically layout- or ABI-affecting (`_ITERATOR_DEBUG_LEVEL`, `_WIN32_WINNT`, `UNICODE`, `FMT_HEADER_ONLY`, `SPDLOG_ACTIVE_LEVEL`), so a member compiled without them is an ODR violation against members compiled with them.

.agents/docs/README.md

@@ -18,7 +18,7 @@ superseded_by: 2026-09-07-....md  # when status is superseded
 ---
 ```
 
-309 records.
+310 records.
 
 ## By subject
 
@@ -30,6 +30,7 @@ Records that declare one. Everything else is listed by date below.
 
 ### design
 
+- [Issues #693 to #696: triage against mcpp's contracts, and one repair plan](2026-09-25-issues-693-696-triage-and-repair-plan.md) — active
 - [Workspace inheritance, flag scoping and the published form: a unified repair plan (#690)](2026-09-25-issue-690-workspace-build-inheritance-consistency.md) — landed
 - [MSVC toolset 的选择、#685、#687 与工具链管理规范：总体设计](2026-09-24-toolchain-selection-and-payload-trust-design.md) — active
 - [openkal 生态：能力的时刻模型，以及 C 环境方案空间的划分](2026-09-20-openkal-c-environment-ecosystem-design.md) — active
@@ -100,6 +101,7 @@ Records that declare one. Everything else is listed by date below.
 
 ### 2026-09
 
+- [Issues #693 to #696: triage against mcpp's contracts, and one repair plan](2026-09-25-issues-693-696-triage-and-repair-plan.md) — active
 - [Workspace inheritance, flag scoping and the published form: a unified repair plan (#690)](2026-09-25-issue-690-workspace-build-inheritance-consistency.md) — landed
 - [#690: self-review before release, engine and ecosystem](2026-09-25-issue-690-self-review.md) — landed
 - [#690: implementation plan](2026-09-25-issue-690-implementation-plan.md) — landed

.github/actions/bootstrap-mcpp/action.yml

@@ -25,7 +25,7 @@ inputs:
     # `package.name`, so one of the two was simply unreachable — and which one
     # depended on the machine, which is why CI failed on `compat:lua` on
     # Windows and `mcpplibs.capi:lua` on Linux. Never pin below that.
-    default: '2026.9.20.1'
+    default: '2026.9.26.2'
   cache-target:
     description: also restore/save target/ (build artifacts + BMIs)
     required: false

.github/actions/setup-macos-llvm/action.yml

@@ -15,7 +15,7 @@ inputs:
     # Floor imposed by the index, not a routine bump — see
     # .github/actions/bootstrap-mcpp/action.yml for why 0.4.69 is required
     # (two packages named `lua` in one repo need openxlings/xlings#381).
-    default: '2026.9.20.1'
+    default: '2026.9.26.2'
   image:
     description: >
       The runner label the job runs on (macos-15, xcode-27). It is part of the

.github/tools/check_unicode_paths.sh

@@ -0,0 +1,130 @@
+#!/usr/bin/env bash
+# check_unicode_paths.sh: mcpp#693 on Windows: a project in a directory whose
+# name is not ASCII builds and runs on every toolchain row, and the files mcpp
+# writes for other tools hold that name in UTF-8.
+#
+# THE SHAPE OF THE FAILURE THIS GUARDS. Up to mcpp 2026.9.25.1 mcpp held paths in
+# the process ANSI code page. A name that page could spell (U+00E9 on code page
+# 1252, every Chinese name on code page 936) reached compile_commands.json as
+# ANSI bytes and failed every build with
+#     error: internal: unhandled exception: [json.exception.type_error.316]
+# and a name it could not spell failed with a narrowing exception. mcpp.exe now
+# declares the UTF-8 code page, build programs are linked with the same
+# declaration, and the response files of the MSVC tools begin with a byte order
+# mark. Each of those is a separate way back to the failure, which is why every
+# row runs in every directory.
+#
+# Rows: llvm (clang++, the Windows default), msvc (cl.exe) and mingw (gcc@16.1.0
+# for x86_64-windows-gnu), each in an ASCII directory, a directory named
+# `caf` + U+00E9 (inside code page 1252) and one named U+6D4B U+8BD5 (outside
+# it). One more project runs a build.mcpp that reads its own directory from the
+# environment and prints it back as an include directory: the round trip of a
+# path through a build program. Names are built from bytes, so this file stays
+# ASCII.
+#
+# Usage: MCPP=<mcpp.exe> bash .github/tools/check_unicode_paths.sh
+set -uo pipefail
+
+: "${MCPP:?set MCPP to the mcpp.exe under test}"
+ROOT=$(mktemp -d)
+CAFE="caf$(printf '\xc3\xa9')"
+CJK="$(printf '\xe6\xb5\x8b\xe8\xaf\x95')"
+CAFE_ANSI="caf$(printf '\xe9')"
+failed=0
+
+ok()  { echo "  ok    $*"; }
+bad() { echo "  FAIL  $*"; failed=1; }
+
+# write_project DIR TOOLCHAIN_LINES
+write_project() {
+    mkdir -p "$1/src"
+    printf '[package]\nname    = "unicodeprobe"\nversion = "0.1.0"\n\n%b\n' "$2" > "$1/mcpp.toml"
+    cat > "$1/src/main.cpp" <<'EOF'
+import std;
+int main() {
+    std::println("unicode probe");
+    return 0;
+}
+EOF
+}
+
+# The generated file holds the directory name in UTF-8, and never in the ANSI
+# code page.
+check_bytes() {
+    local file=$1 name=$2 row=$3
+    [ -f "$file" ] || { bad "$row: no $(basename "$file")"; return; }
+    if ! LC_ALL=C grep -qF "$name" "$file"; then
+        bad "$row: $(basename "$file") does not hold the directory name in UTF-8"
+    fi
+    if [ "$name" = "$CAFE" ] && LC_ALL=C grep -qF "$CAFE_ANSI" "$file"; then
+        bad "$row: $(basename "$file") holds the ANSI spelling of the directory name"
+    fi
+}
+
+rows=(
+    'llvm|[toolchain]\nwindows = "llvm@20.1.7"|'
+    'msvc|[toolchain]\nwindows = "msvc@system"|'
+    'mingw|[toolchain]\ndefault = "gcc@16.1.0"|--target x86_64-windows-gnu'
+)
+
+for name in ascii "$CAFE" "$CJK"; do
+    for row in "${rows[@]}"; do
+        IFS='|' read -r rid tc args <<<"$row"
+        dir="$ROOT/$name/$rid"
+        label="$rid in '$name'"
+        write_project "$dir" "$tc"
+        cd "$dir" || { bad "$label: cannot enter the directory"; continue; }
+        # shellcheck disable=SC2086
+        if ! "$MCPP" build $args > build.log 2>&1; then
+            bad "$label: the build failed"; tail -15 build.log | sed 's/^/          /'; continue
+        fi
+        # shellcheck disable=SC2086
+        out=$("$MCPP" run $args 2>&1)
+        if ! grep -q 'unicode probe' <<<"$out"; then
+            bad "$label: the program did not run"; printf '%s\n' "$out" | tail -5 | sed 's/^/          /'
+            continue
+        fi
+        if [ "$name" != ascii ]; then
+            ninja=$(find target -name build.ninja -newer mcpp.toml | head -1)
+            check_bytes "$ninja" "$name" "$label"
+            check_bytes compile_commands.json "$name" "$label"
+        fi
+        ok "$label"
+    done
+done
+
+# A path through a build program: MCPP_MANIFEST_DIR in, `mcpp:include-dir` out,
+# and the header found at the directory the program printed.
+dir="$ROOT/$CJK/buildprogram"
+mkdir -p "$dir/src" "$dir/inc"
+printf '[package]\nname    = "unicodebp"\nversion = "0.1.0"\n\n[toolchain]\nwindows = "llvm@20.1.7"\n' > "$dir/mcpp.toml"
+printf '#define UNICODE_BP 42\n' > "$dir/inc/unicode_bp.h"
+cat > "$dir/build.mcpp" <<'EOF'
+#include <cstdio>
+#include <cstdlib>
+int main() {
+    const char* here = std::getenv("MCPP_MANIFEST_DIR");
+    if (!here) return 1;
+    std::printf("mcpp:include-dir=%s/inc\n", here);
+    return 0;
+}
+EOF
+cat > "$dir/src/main.cpp" <<'EOF'
+#include "unicode_bp.h"
+import std;
+int main() {
+    std::println("build program {}", UNICODE_BP);
+    return 0;
+}
+EOF
+cd "$dir"
+if "$MCPP" build > build.log 2>&1 && "$MCPP" run 2>&1 | grep -q 'build program 42'; then
+    ok "a path through build.mcpp in '$CJK'"
+else
+    bad "a path through build.mcpp in '$CJK'"; tail -15 build.log | sed 's/^/          /'
+fi
+
+cd / && rm -rf "$ROOT"
+[ "$failed" = 0 ] && echo "OK: every row builds in every directory" && exit 0
+echo "FAIL: at least one row did not build in a directory whose name is not ASCII"
+exit 1

.github/workflows/bootstrap-macos.yml

@@ -17,7 +17,7 @@ jobs:
       # Dormant (workflow_dispatch only), but kept in step with the rest —
       # check_version_pins.sh holds it there. Floor: 0.4.69, below which the
       # index cannot resolve two packages that share a short name.
-      XLINGS_VERSION: '2026.9.20.1'
+      XLINGS_VERSION: '2026.9.26.2'
     steps:
       - uses: actions/checkout@v4
 

.github/workflows/ci-fresh-install.yml

@@ -152,7 +152,7 @@ jobs:
         env:
           XLINGS_NON_INTERACTIVE: '1'
         run: |
-          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh | bash -s v2026.9.20.1
+          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh | bash -s v2026.9.26.2
           echo "$HOME/.xlings/subos/current/bin" >> "$GITHUB_PATH"
 
       - name: Install mcpp and config mirror
@@ -312,7 +312,7 @@ jobs:
 
       - name: Install xlings + mcpp
         run: |
-          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh | bash -s v2026.9.20.1
+          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh | bash -s v2026.9.26.2
           # Deliberately NOT writing to $GITHUB_PATH here. On container
           # images that declare no PATH in their config (opensuse/
           # tumbleweed), appending a single dir to GITHUB_PATH makes the
@@ -403,7 +403,7 @@ jobs:
           #             (older ones carry minos=15 and refuse to start).
           #   v0.4.51+: in-process sha256 — this image has no sha256sum
           #             binary, so pinned fetches failed before it.
-          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh | bash -s v2026.9.20.1
+          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh | bash -s v2026.9.26.2
           echo "$HOME/.xlings/subos/current/bin" >> "$GITHUB_PATH"
 
       - name: Install mcpp and config mirror

.github/workflows/ci-linux-e2e.yml

@@ -384,7 +384,7 @@ jobs:
 
       - name: Bootstrap xlings + released mcpp
         run: |
-          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh | bash -s v2026.9.20.1
+          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh | bash -s v2026.9.26.2
           export PATH="$HOME/.xlings/subos/current/bin:$PATH"
           xlings update
           xlings install mcpp -y -g

.github/workflows/ci-windows.yml

@@ -405,6 +405,17 @@ jobs:
           # restore the LLVM default for the remaining steps
           "$MCPP_SELF" toolchain default llvm@20.1.7
 
+      # mcpp#693: a project in a directory whose name is not ASCII, inside the
+      # runner's code page 1252 and outside it, on the llvm, MSVC and MinGW rows,
+      # plus a path carried through build.mcpp. Each row reaches a different
+      # consumer of mcpp's text: Ninja's build file, the MSVC response files,
+      # and the MinGW driver.
+      - name: "Paths: non-ASCII project directories on every toolchain row (mcpp#693)"
+        shell: bash
+        run: |
+          export MCPP_VENDORED_XLINGS="$XLINGS_BIN"
+          MCPP="$MCPP_SELF" bash .github/tools/check_unicode_paths.sh
+
 
       # GRAPHICS ON THIS HOST, BUILD ONLY, AND THAT IS THE WHOLE CLAIM.
       #

.github/workflows/cross-build-test.yml

@@ -135,7 +135,7 @@ jobs:
           # release assets were uploaded in a broken state (records present,
           # blobs missing → 404 on GET); re-uploaded clean. The stale-INDEX
           # half is handled by the marker-clear below.
-          XLINGS_VERSION: '2026.9.20.1'
+          XLINGS_VERSION: '2026.9.26.2'
         run: |
           tarball="xlings-${XLINGS_VERSION}-linux-x86_64.tar.gz"
           bash "$GITHUB_WORKSPACE/.github/tools/fetch_release.sh" \
@@ -289,7 +289,7 @@ jobs:
       - name: Bootstrap mcpp via xlings
         env:
           XLINGS_NON_INTERACTIVE: '1'
-          XLINGS_VERSION: '2026.9.20.1'
+          XLINGS_VERSION: '2026.9.26.2'
         run: |
           tarball="xlings-${XLINGS_VERSION}-linux-x86_64.tar.gz"
           bash "$GITHUB_WORKSPACE/.github/tools/fetch_release.sh" \

.github/workflows/openkal-cross.yml

@@ -576,7 +576,7 @@ jobs:
           for t in tests/e2e/285_*.sh tests/e2e/286_*.sh tests/e2e/287_*.sh \
                    tests/e2e/288_*.sh tests/e2e/289_*.sh tests/e2e/291_*.sh \
                    tests/e2e/292_*.sh tests/e2e/293_*.sh tests/e2e/294_*.sh \
-                   tests/e2e/738_*.sh; do
+                   tests/e2e/738_*.sh tests/e2e/778_*.sh; do
             echo "=== $t ==="
             bash "$t" 2>&1 | tee "$(basename "$t").log" || true
             rc=${PIPESTATUS[0]}
@@ -630,4 +630,15 @@ jobs:
             "OK: the list answers what can be built, not what has a payload" || fail=1
           check 738_a_graph_supplied_target_closes_the_hosts_own_search.sh \
             "PASS: 738 a graph-supplied target closes the host's own search" || fail=1
+          # mcpp#696, the link-side twin of 738: both legs, because the one
+          # that separates the engines is the refusal, and a skip of either
+          # prints the final line all the same.
+          check 778_a_graph_link_searches_no_host_directory.sh \
+            "ok: -lm is answered by openkal-musl's own archive, and the program runs" || fail=1
+          check 778_a_graph_link_searches_no_host_directory.sh \
+            "ok: an unanswered -lm fails, and the note names openkal-musl 0.19.2" || fail=1
+          check 778_a_graph_link_searches_no_host_directory.sh \
+            "ok: aarch64-linux-musl links -lm from the graph and runs under qemu-aarch64" || fail=1
+          check 778_a_graph_link_searches_no_host_directory.sh \
+            "ok: a host directory in ldflags is refused, by name" || fail=1
           [ "$fail" = 0 ] || exit 1

.github/workflows/release.yml

@@ -96,7 +96,7 @@ jobs:
           # Pin xlings to a known-good version. The upstream install
           # script always grabs `latest` (no version override), so we
           # download + self-install manually to avoid broken releases.
-          XLINGS_VERSION: '2026.9.20.1'
+          XLINGS_VERSION: '2026.9.26.2'
         run: |
           if [ ! -x "$HOME/.xlings/subos/default/bin/xlings" ]; then
             tarball="xlings-${XLINGS_VERSION}-linux-x86_64.tar.gz"
@@ -314,7 +314,7 @@ jobs:
       - name: Bootstrap mcpp via xlings
         env:
           XLINGS_NON_INTERACTIVE: '1'
-          XLINGS_VERSION: '2026.9.20.1'
+          XLINGS_VERSION: '2026.9.26.2'
         run: |
           tarball="xlings-${XLINGS_VERSION}-linux-x86_64.tar.gz"
           bash "$GITHUB_WORKSPACE/.github/tools/fetch_release.sh" \
@@ -385,7 +385,7 @@ jobs:
           # below are pinned to the same version as XLINGS_VERSION; they are
           # NOT interpolated from it, so check_version_pins.sh scans for them
           # explicitly (they were absent from the old lock-step comment).
-          XLA="xlings-2026.9.20.1-linux-aarch64.tar.gz"
+          XLA="xlings-2026.9.26.2-linux-aarch64.tar.gz"
           # NOT fetch_release.sh: this asset is OPTIONAL and the `if` is the
           # point — an arch with no prebuilt xlings must fall through quietly,
           # while the helper retries a 404 five times before giving up. The one
@@ -394,9 +394,9 @@ jobs:
           # cover it.
           if curl -fsSL --retry 3 --retry-delay 2 --retry-all-errors \
                --connect-timeout 20 --max-time 600 -o "/tmp/$XLA" \
-               "https://github.com/openxlings/xlings/releases/download/v2026.9.20.1/$XLA"; then
+               "https://github.com/openxlings/xlings/releases/download/v2026.9.26.2/$XLA"; then
             tar -xzf "/tmp/$XLA" -C /tmp
-            XLBIN=$(find /tmp/xlings-2026.9.20.1-linux-aarch64 -path '*/bin/xlings' -type f | head -1)
+            XLBIN=$(find /tmp/xlings-2026.9.26.2-linux-aarch64 -path '*/bin/xlings' -type f | head -1)
             if [ -n "$XLBIN" ]; then
               mkdir -p "$STAGING/$WRAPPER/registry/bin"
               cp "$XLBIN" "$STAGING/$WRAPPER/registry/bin/xlings"
@@ -474,7 +474,7 @@ jobs:
       - name: Bootstrap mcpp via xlings
         env:
           XLINGS_NON_INTERACTIVE: '1'
-          XLINGS_VERSION: '2026.9.20.1'
+          XLINGS_VERSION: '2026.9.26.2'
         run: |
           if [ ! -x "$HOME/.xlings/subos/default/bin/xlings" ]; then
             WORK=$(mktemp -d)
@@ -657,7 +657,7 @@ jobs:
         shell: bash
         env:
           XLINGS_NON_INTERACTIVE: '1'
-          XLINGS_VERSION: '2026.9.20.1'
+          XLINGS_VERSION: '2026.9.26.2'
         run: |
           # Captured before the `cd` below, in POSIX form: this step never
           # returns to the workspace, and GITHUB_WORKSPACE is a backslash