test(ci): carry Windows rename probe through supervisor log

Author: Sunrisepeak

src/build/schedule/compiler_transaction.cpp

@@ -32,6 +32,7 @@ bool replace_record(const fs::path& path,std::string_view bytes,std::string* dia
             std::error_code sourceError, targetError;
             const auto source=fs::symlink_status(temporary,sourceError);
             const auto target=fs::symlink_status(path,targetError);
+            std::string probeReport;
             // A final status is a new name. If the replace form itself was
             // refused as invalid while that name is absent, try the atomic
             // no-replace form on the exact same source and destination. Its
@@ -60,18 +61,18 @@ bool replace_record(const fs::path& path,std::string_view bytes,std::string* dia
                 std::error_code nativeError;
                 fs::rename(temporary,probe,nativeError);
                 if(!nativeError) {std::error_code ignored;fs::remove(probe,ignored);}
-                std::println(std::cerr,
-                    "mcpp: CI rename probe source-rel {} target-rel {} same-root {} KAL-read {} std-rename-code {} category {}",
+                probeReport=std::format(
+                    "; CI probe source-rel {} target-rel {} same-root {} KAL-read {} std-rename-code {} category {}",
                     sourceLocation?sourceLocation->relative.size():0,
                     targetLocation?targetLocation->relative.size():0,
                     sourceLocation&&targetLocation&&sourceLocation->directory==targetLocation->directory,
                     readable?0:static_cast<int>(readable.error().code),
                     nativeError.value(),nativeError.category().name());
             }
 #endif
-            *diagnostic=std::format("rename temporary (condition {}, native {}; source regular {} ec {}; target exists {} ec {}; no-replace condition {})",
+            *diagnostic=std::format("rename temporary (condition {}, native {}; source regular {} ec {}; target exists {} ec {}; no-replace condition {}{})",
                 static_cast<int>(renamed.error().code),renamed.error().native,
-                fs::is_regular_file(source),sourceError.value(),fs::exists(target),targetError.value(),noReplaceCode);
+                fs::is_regular_file(source),sourceError.value(),fs::exists(target),targetError.value(),noReplaceCode,probeReport);
         }
     } else if(!written) {
         fail("write/flush temporary");

src/build/schedule/detach_codegen.cppm

@@ -312,6 +312,7 @@ std::optional<int> read_rc(const std::filesystem::path& slot) {
 
 // Temp file + rename, so a reader never observes half a number. The same
 // guarantee, for the same reason, that makes watching the BMI path sound.
+void record_supervisor_error(const std::filesystem::path& slot,std::string_view reason);
 bool write_rc(const std::filesystem::path& slot, int rc,std::string* diagnostic=nullptr) {
     std::string localDiagnostic;
     auto* detail=diagnostic?diagnostic:&localDiagnostic;
@@ -320,7 +321,7 @@ bool write_rc(const std::filesystem::path& slot, int rc,std::string* diagnostic=
     // CI-only: early supervisor failures have no caller-owned diagnostic.
     // Report their status-publication failure without printing private paths.
     if(!written&&!diagnostic)
-        std::println(std::cerr,"mcpp: CI early status publication: {}",localDiagnostic);
+        record_supervisor_error(slot,std::format("CI early status publication: {}",localDiagnostic));
 #endif
     return written;
 }