fix(linters): pass build_base to linters and avoid hardcoded fallback…

snapcraft/linters/base.py

@@ -93,10 +93,12 @@ def __init__(
         name: str,
         snap_metadata: "SnapMetadata",
         lint: models.Lint | None,
+        build_base: str | None = None,
     ):
         self._name = name
         self._snap_metadata = snap_metadata
         self._lint = lint or models.Lint(ignore=[])
+        self._build_base = build_base
 
     @abc.abstractmethod
     def run(self) -> list[LinterIssue]:

snapcraft/linters/gpu_linter.py

@@ -83,9 +83,9 @@ def run(self) -> list[LinterIssue]:
         current_path = Path()
         issues: list[LinterIssue] = []
 
-        base = self._snap_metadata.base or "core24"
+        base = self._snap_metadata.base or self._build_base or "core24"
         if base == "bare":
-            base = "core24"
+            base = self._build_base or "core24"
 
         elf_files = elf_utils.get_elf_files(current_path)
 

snapcraft/linters/linters.py

@@ -136,7 +136,9 @@ def _update_status(status: LinterStatus, result: LinterResult) -> LinterStatus:
     return status
 
 
-def run_linters(location: Path, *, lint: models.Lint | None) -> list[LinterIssue]:
+def run_linters(
+    location: Path, *, lint: models.Lint | None, build_base: str | None = None
+) -> list[LinterIssue]:
     """Run all the defined linters.
 
     :param location: The root of the snap payload subtree to run linters on.

tests/unit/linters/test_gpu_linter.py

@@ -411,5 +411,57 @@ def test_gpu_linter_classic_confinement(mocker, new_dir, mock_elf_files, base, f
 
     issues = linters.run_linters(new_dir, lint=None)
 
-    # Classic confinement snaps should never trigger GPU linter warnings
     assert len(issues) == 0
+
+
+@pytest.mark.parametrize(
+    "base,build_base,expected_url",
+    [
+        pytest.param(
+            "bare",
+            "core26",
+            "https://ubuntu.com/frame/docs/26/how-to/use-snap-graphics/",
+            id="bare-with-build-base",
+        ),
+        pytest.param(
+            None,
+            "core22",
+            "https://ubuntu.com/frame/docs/22/how-to/use-snap-graphics/",
+            id="none-with-build-base",
+        ),
+        pytest.param(
+            "bare",
+            None,
+            "https://ubuntu.com/frame/docs/24/how-to/use-snap-graphics/",
+            id="bare-no-build-base-fallback",
+        ),
+    ],
+)
+def test_gpu_linter_build_base(mocker, base, build_base, expected_url):
+    """Test that GPU linter respects build_base when base is bare or undefined."""
+    # 1. Create a dummy file object
+    mock_elf = Mock()
+    mock_elf.path = "lib/x86_64-linux-gnu/libGL.so.1"
+
+    # 2. Mock the file reader
+    mocker.patch(
+        "snapcraft.linters.gpu_linter.elf_utils.get_elf_files", return_value=[mock_elf]
+    )
+
+    # 3. Create a simple mock metadata object
+    mock_metadata = Mock()
+    mock_metadata.type = "app"
+    mock_metadata.confinement = "strict"
+    mock_metadata.base = base
+
+    # 4. Instantiate the linter DIRECTLY
+    linter = GpuLinter(
+        name="gpu", snap_metadata=mock_metadata, lint=None, build_base=build_base
+    )
+
+    # 5. Run the linter
+    issues = linter.run()
+
+    # 6. Verify the URL logic
+    assert len(issues) == 1
+    assert issues[0].url == expected_url