test(ci): isolate macOS Android install and diagnose Windows record rename

Author: Sunrisepeak

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

@@ -52,6 +52,9 @@ jobs:
     timeout-minutes: 60
     env:
       E2E_SHARD: ${{ matrix.shard }}/${{ matrix.shards }}
+      # 721 installs the large NDK in its own bounded step below. Running it in
+      # the ordinary shard duplicates the download and can fail before linking.
+      E2E_EXCLUDE: 721_*.sh
       E2E_TIMINGS: tests/e2e/timings/macos.tsv
       E2E_REPORT: ${{ github.workspace }}/e2e-report-${{ matrix.image == 'macos-15' && 'macos' || matrix.image }}-${{ matrix.shard }}.tsv
     # NOTE: no MCPP_VERBOSE — the e2e suite asserts mcpp's default quiet

src/build/schedule/compiler_transaction.cpp

@@ -25,8 +25,17 @@ bool replace_record(const fs::path& path,std::string_view bytes,std::string* dia
     if(written&&closed) {
         auto renamed=os::fs::rename(temporary,path,true);
         if(renamed)return true;
-        if(diagnostic)*diagnostic=std::format("rename temporary (condition {}, native {})",
-            static_cast<int>(renamed.error().code),renamed.error().native);
+        if(diagnostic) {
+            // The OpenKal condition does not retain the Windows NTSTATUS. These
+            // observations distinguish a blocked replacement from a source or
+            // parent failure without exposing private build paths in CI logs.
+            std::error_code sourceError, targetError;
+            const auto source=fs::symlink_status(temporary,sourceError);
+            const auto target=fs::symlink_status(path,targetError);
+            *diagnostic=std::format("rename temporary (condition {}, native {}; source regular {} ec {}; target exists {} ec {})",
+                static_cast<int>(renamed.error().code),renamed.error().native,
+                fs::is_regular_file(source),sourceError.value(),fs::exists(target),targetError.value());
+        }
     } else if(!written) {
         fail("write/flush temporary");
     } else {

tests/e2e/run_all.sh

@@ -468,8 +468,8 @@ report() {
 }
 if [[ -n "${E2E_REPORT:-}" ]]; then : > "$E2E_REPORT"; fi
 
-# E2E_LIST=1 prints the tests this invocation would run (after E2E_ONLY and the
-# shard, before the capability check) and exits, so a shard's membership can be
+# E2E_LIST=1 prints the tests this invocation would run (after E2E_ONLY,
+# E2E_EXCLUDE and the shard, before the capability check) and exits, so a shard's membership can be
 # read without running it.
 if [[ "${E2E_LIST:-}" == "1" ]]; then
     for test in "$HERE"/[0-9]*.sh; do
@@ -478,6 +478,10 @@ if [[ "${E2E_LIST:-}" == "1" ]]; then
             # shellcheck disable=SC2053 -- glob match is the point
             [[ "$name" == $E2E_ONLY ]] || continue
         fi
+        if [[ -n "${E2E_EXCLUDE:-}" ]]; then
+            # shellcheck disable=SC2053 -- glob match is the point
+            [[ "$name" == $E2E_EXCLUDE ]] && continue
+        fi
         if (( SHARD_TOTAL > 1 )); then in_shard "$name" || continue; fi
         echo "$name"
     done
@@ -496,6 +500,15 @@ for test in "$HERE"/[0-9]*.sh; do
     if (( SHARD_TOTAL > 1 )); then
         in_shard "$name" || continue
     fi
+    if [[ -n "${E2E_EXCLUDE:-}" ]]; then
+        # shellcheck disable=SC2053 -- glob match is the point
+        if [[ "$name" == $E2E_EXCLUDE ]]; then
+            echo "SKIP: $name (owned by a dedicated workflow step)"
+            ((SKIP++))
+            report skip "$name" 0 "owned by a dedicated workflow step"
+            continue
+        fi
+    fi
     echo
     missing_cap="$(check_requires "$test")"
     if [[ -n "$missing_cap" ]]; then

tests/unit/test_compiler_transaction.cpp

@@ -237,6 +237,19 @@ TEST(CompilerTransaction, FailedRenameReportsTheStageAndPreservesItsTarget) {
     EXPECT_TRUE(diagnostic.starts_with("rename temporary (condition "))<<diagnostic;
     EXPECT_TRUE(fs::is_directory(t.root/"record"));
 }
+TEST(CompilerTransaction, ReaderHeldTargetKeepsAnAtomicRecord) {
+    Transaction t;
+    const auto record=t.root/"record";
+    std::ofstream(record)<<"old";
+    std::ifstream held(record,std::ios::binary);
+    ASSERT_TRUE(held);
+    std::string diagnostic;
+    const bool replaced=tx::replace_record(record,"new",&diagnostic);
+    std::cout<<"READING reader-held record replacement: "
+             <<(replaced?"replaced":diagnostic)<<'\n';
+    EXPECT_EQ(Transaction::contents(record),replaced?"new":"old");
+    EXPECT_EQ(std::string(std::istreambuf_iterator<char>(held),std::istreambuf_iterator<char>()),"old");
+}
 TEST(CompilerTransaction, RecordOpenAppearanceDriver) {
     if(!mcpp::invocation::get("MCPP_TEST_RECORD_OPEN_DRIVER"))GTEST_SKIP()<<"subprocess driver";
     auto record=tx::read("record","schema");