ignoreException has been split into two

The Finally part is a destructor, so using `ignoreExceptionInDestructor`
seems to be the correct choice here.

.envrc

@@ -1 +1 @@
-use flake
+use flake .#clang

flake.lock

@@ -48,11 +48,11 @@
         "pre-commit-hooks": "pre-commit-hooks"
       },
       "locked": {
-        "lastModified": 1728159440,
-        "narHash": "sha256-8DW+VfSIk5xYpYj1VDKMmUjXhMooIlAOwYG4J9PLbbg=",
+        "lastModified": 1728163191,
+        "narHash": "sha256-SW0IEBsPN1EysqzvfDT+8Kimtzy03O1BxQQm7ZB6fRY=",
         "ref": "refs/heads/main",
-        "rev": "7ff60b7445ccb599edcbf0078d181034f61a0859",
-        "revCount": 16318,
+        "rev": "ed9b7f4f84fd60ad8618645cc1bae2d686ff0db6",
+        "revCount": 16323,
         "type": "git",
         "url": "https://git.lix.systems/lix-project/lix"
       },
@@ -126,11 +126,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1725001927,
-        "narHash": "sha256-eV+63gK0Mp7ygCR0Oy4yIYSNcum2VQwnZamHxYTNi+M=",
+        "lastModified": 1728193676,
+        "narHash": "sha256-PbDWAIjKJdlVg+qQRhzdSor04bAPApDqIv2DofTyynk=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "6e99f2a27d600612004fbd2c3282d614bfee6421",
+        "rev": "ecbc1ca8ffd6aea8372ad16be9ebbb39889e55b6",
         "type": "github"
       },
       "original": {

src/hydra-queue-runner/builder.cc

@@ -1,5 +1,6 @@
 #include <cmath>
 
+#include "error.hh"
 #include "state.hh"
 #include "hydra-build-result.hh"
 #include "finally.hh"
@@ -185,7 +186,7 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
                     unlink(result.logFile.c_str());
                 }
             } catch (...) {
-                ignoreException();
+                ignoreExceptionInDestructor();
             }
         }
     });

src/hydra-queue-runner/nar-extractor.cc

@@ -7,8 +7,37 @@
 
 using namespace nix;
 
-struct Extractor : ParseSink
+struct Extractor : NARParseVisitor
 {
+    class MyFileHandle : public FileHandle
+    {
+        NarMemberData & memberData;
+        uint64_t expectedSize;
+        std::unique_ptr<HashSink> hashSink;
+
+        public:
+            MyFileHandle(NarMemberData & memberData, uint64_t size) : memberData(memberData), expectedSize(size)
+            {
+                hashSink = std::make_unique<HashSink>(HashType::SHA256);
+            }
+
+            void receiveContents(std::string_view data) override
+            {
+                *memberData.fileSize += data.size();
+                (*hashSink)(data);
+                if (memberData.contents) {
+                    memberData.contents->append(data);
+                }
+                assert(memberData.fileSize <= expectedSize);
+                if (memberData.fileSize == expectedSize) {
+                    auto [hash, len] = hashSink->finish();
+                    assert(memberData.fileSize == len);
+                    memberData.sha256 = hash;
+                    hashSink.reset();
+                }
+            }
+    };
+
     std::unordered_set<Path> filesToKeep {
         "/nix-support/hydra-build-products",
         "/nix-support/hydra-release-name",
@@ -16,7 +45,6 @@ struct Extractor : ParseSink
     };
 
     NarMemberDatas & members;
-    NarMemberData * curMember = nullptr;
     Path prefix;
 
     Extractor(NarMemberDatas & members, Path  prefix)
@@ -28,41 +56,15 @@ struct Extractor : ParseSink
         members.insert_or_assign(prefix + path, NarMemberData { .type = FSAccessor::Type::tDirectory });
     }
 
-    void createRegularFile(const Path & path) override
+    std::unique_ptr<FileHandle> createRegularFile(const Path & path, uint64_t size, bool executable) override
     {
-        curMember = &members.insert_or_assign(prefix + path, NarMemberData {
+        auto memberData = &members.insert_or_assign(prefix + path, NarMemberData {
             .type = FSAccessor::Type::tRegular,
             .fileSize = 0,
             .contents = filesToKeep.count(path) ? std::optional("") : std::nullopt,
         }).first->second;
-    }
 
-    std::optional<uint64_t> expectedSize;
-    std::unique_ptr<HashSink> hashSink;
-
-    void preallocateContents(uint64_t size) override
-    {
-        expectedSize = size;
-        hashSink = std::make_unique<HashSink>(HashType::SHA256);
-    }
-
-    void receiveContents(std::string_view data) override
-    {
-        assert(expectedSize);
-        assert(curMember);
-        assert(hashSink);
-        *curMember->fileSize += data.size();
-        (*hashSink)(data);
-        if (curMember->contents) {
-            curMember->contents->append(data);
-        }
-        assert(curMember->fileSize <= expectedSize);
-        if (curMember->fileSize == expectedSize) {
-            auto [hash, len] = hashSink->finish();
-            assert(curMember->fileSize == len);
-            curMember->sha256 = hash;
-            hashSink.reset();
-        }
+        return std::make_unique<MyFileHandle>(*memberData, size);
     }
 
     void createSymlink(const Path & path, const std::string & target) override