diff --git a/overlays/test-exclusions.nix b/overlays/test-exclusions.nix
index 41a6d5a..e410525 100644
--- a/overlays/test-exclusions.nix
+++ b/overlays/test-exclusions.nix
@@ -111,6 +111,15 @@ _final: prev: {
         ];
       });
 
+      torchaudio = pythonPrev.torchaudio.overridePythonAttrs (old: {
+        # x86-64-v3 pitch shifting produces batch-versus-single-item numerical
+        # differences up to 2.9e-6. We accept that audio-precision risk for our
+        # workloads.
+        disabledTests = (old.disabledTests or [ ]) ++ [
+          "test_batch_pitch_shift"
+        ];
+      });
+
       torchcodec = pythonPrev.torchcodec.overridePythonAttrs (old: {
         # For these 8 kHz MP3 cases, the x86-64-v3 API and CLI codec paths
         # differ in 0.8% of decoded samples. Retain the original tolerance for
diff --git a/overlays/x86-64-v3-workarounds.nix b/overlays/x86-64-v3-workarounds.nix
index 6f8a390..c1e0bd0 100644
--- a/overlays/x86-64-v3-workarounds.nix
+++ b/overlays/x86-64-v3-workarounds.nix
@@ -4,17 +4,57 @@
 # by the generic x86-64 build. Keep compile fixes here, separate from test
 # exclusions, until upstream or nixpkgs incorporates them.
 _final: prev:
+let
+  patchAbseilBmi2Include =
+    package:
+    package.overrideAttrs (old: {
+      # GCC and Clang prohibit including their internal BMI2 header directly.
+      # The public umbrella provides the same intrinsics with the required
+      # compiler setup.
+      postPatch = (old.postPatch or "") + ''
+        substituteInPlace third_party/abseil-cpp/absl/container/internal/raw_hash_set.h \
+          --replace-fail "#include <bmi2intrin.h>" "#include <immintrin.h>"
+      '';
+    });
+
+  removeSiblingOutputChecks =
+    package:
+    package.overrideAttrs (old: {
+      # Nix 2.34 can validate a partial multi-output rebuild against only the
+      # outputs still being realised. PostgreSQL's checks then reject valid
+      # sibling names such as "out" and "lib". Keep the test suite and
+      # disallowed-requisite checks; accept the loss of cross-output checks.
+      outputChecks = builtins.mapAttrs (
+        _output: checks: builtins.removeAttrs checks [ "disallowedReferences" ]
+      ) (old.outputChecks or { });
+    });
+
+  electron43Unwrapped = patchAbseilBmi2Include prev.electron_43.unwrapped;
+  electron43 = prev.electron_43.override {
+    electron-unwrapped = electron43Unwrapped;
+  };
+
+  signalCallPackage =
+    path: args:
+    let
+      package = prev.callPackage path args;
+    in
+    if builtins.baseNameOf path == "webrtc.nix" then patchAbseilBmi2Include package else package;
+in
 prev.lib.optionalAttrs ((prev.stdenv.hostPlatform.gcc.arch or null) == "x86-64-v3") {
   deno =
     let
-      librusty_v8 = prev.deno.passthru.librusty_v8.overrideAttrs (old: {
-        # Clang prohibits including its internal BMI2 header directly. The
-        # public umbrella supplies the same intrinsics with the required setup.
-        postPatch = (old.postPatch or "") + ''
-          substituteInPlace third_party/abseil-cpp/absl/container/internal/raw_hash_set.h \
-            --replace-fail "#include <bmi2intrin.h>" "#include <immintrin.h>"
-        '';
-      });
+      librusty_v8 = patchAbseilBmi2Include prev.deno.passthru.librusty_v8;
     in
     prev.deno.override { inherit librusty_v8; };
+
+  electron_43 = electron43;
+
+  postgresql = removeSiblingOutputChecks prev.postgresql;
+  postgresql_18 = removeSiblingOutputChecks prev.postgresql_18;
+
+  signal-desktop = prev.signal-desktop.override {
+    electron_43 = electron43;
+    callPackage = signalCallPackage;
+  };
 }