feat: use blacksmith for nixos tests on aarch64-linux

.github/actions/nix-install-ephemeral/action.yml

@@ -49,3 +49,7 @@ runs:
           trusted-public-keys = nix-postgres-artifacts:dGZlQOvKcNEjvT7QEAJbcV6b6uk7VF/hWMjhYleiaLI= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
           ${{ inputs.push-to-cache == 'true' && 'post-build-hook = /etc/nix/upload-to-cache.sh' || '' }}
           max-jobs = 4
+    - name: Test KVM support
+      shell: bash
+      run: |
+        ls -l /dev/kvm || echo "KVM support not available"

nix/ext/tests/pgrouting.nix

@@ -36,6 +36,7 @@ pkgs.testers.runNixOSTest {
     in
     ''
       from pathlib import Path
+
       versions = {
         "15": [${lib.concatStringsSep ", " (map (s: ''"${s}"'') (versions "15"))}],
         "17": [${lib.concatStringsSep ", " (map (s: ''"${s}"'') (versions "17"))}],

nix/packages/github-matrix/github_matrix.py

@@ -81,10 +81,6 @@ class NixEvalError(TypedDict):
             "group": "self-hosted-runners-nix",
             "labels": ["aarch64-darwin"],
         },
-        "aarch64-linux": {
-            "group": "self-hosted-runners-nix",
-            "labels": ["aarch64-linux"],
-        },
     },
 }
 
@@ -251,18 +247,21 @@ def get_runner_for_package(pkg: NixEvalJobsOutput) -> RunsOnConfig | None:
     """Determine the appropriate GitHub Actions runner for a package.
 
     Priority order:
-    1. KVM packages → self-hosted runners
-    2. Large packages on Linux → 32vcpu ephemeral runners
-    3. Darwin packages → self-hosted runners
-    4. Default → ephemeral runners
+    1. KVM packages on Darwin → self-hosted runners
+    2. KVM packages on Linux → ephemeral runners
+    3. Large packages on Linux → 32vcpu ephemeral runners
+    4. Darwin packages → self-hosted runners
+    5. Default → ephemeral runners
     """
     system = pkg["system"]
 
     if is_kvm_pkg(pkg):
-        runConfig = BUILD_RUNNER_MAP["self-hosted"].get(system)
+        if system == "aarch64-darwin":
+            return BUILD_RUNNER_MAP["self-hosted"]["aarch64-darwin"]
+        runConfig = BUILD_RUNNER_MAP["ephemeral"].get(system)
         if runConfig is None:
             raise ValueError(
-                f"No self-hosted with kvm support available for system: {system}"
+                f"No ephemeral runner with kvm support available for system: {system}"
             )
         return runConfig
 

nix/packages/github-matrix/tests/test_github_matrix.py

@@ -103,11 +103,8 @@ def test_kvm_package_x86_64_linux(self):
             "system": "x86_64-linux",
             "requiredSystemFeatures": ["kvm"],
         }
-        with pytest.raises(
-            ValueError,
-            match=r"No self-hosted with kvm support available for system: x86_64-linux",
-        ):
-            get_runner_for_package(pkg)
+        result = get_runner_for_package(pkg)
+        assert result == {"labels": ["blacksmith-8vcpu-ubuntu-2404"]}
 
     def test_kvm_package_aarch64_linux(self):
         pkg: NixEvalJobsOutput = {
@@ -120,9 +117,22 @@ def test_kvm_package_aarch64_linux(self):
             "requiredSystemFeatures": ["kvm"],
         }
         result = get_runner_for_package(pkg)
+        assert result == {"labels": ["blacksmith-8vcpu-ubuntu-2404-arm"]}
+
+    def test_kvm_package_aarch64_darwin(self):
+        pkg: NixEvalJobsOutput = {
+            "attr": "packages.aarch64-darwin.vm-test",
+            "attrPath": ["packages", "aarch64-darwin", "vm-test"],
+            "cacheStatus": "notBuilt",
+            "drvPath": "/nix/store/test.drv",
+            "name": "vm-test",
+            "system": "aarch64-darwin",
+            "requiredSystemFeatures": ["kvm"],
+        }
+        result = get_runner_for_package(pkg)
         assert result == {
             "group": "self-hosted-runners-nix",
-            "labels": ["aarch64-linux"],
+            "labels": ["aarch64-darwin"],
         }
 
     def test_large_package_x86_64_linux(self):