fix(project): improve error message for unsupported architectures

Signed-off-by: Callahan Kovacs <[email protected]>

snapcraft/projects.py

@@ -32,6 +32,8 @@
     convert_architecture_deb_to_platform,
     get_effective_base,
     get_host_architecture,
+    get_supported_architectures,
+    is_architecture_supported,
 )
 
 
@@ -119,6 +121,19 @@ def _validate_architectures(architectures):
                     )
                 unique_build_fors.add(architecture)
 
+    # validate architectures are supported
+    if len(architectures):
+        for element in architectures:
+            for arch in element.build_for + element.build_on:
+                if arch != "all" and not is_architecture_supported(arch):
+                    supported_archs = utils.humanize_list(
+                        get_supported_architectures(), "and"
+                    )
+                    raise ValueError(
+                        f"Architecture {arch!r} is not supported. Supported "
+                        f"architectures are {supported_archs}."
+                    )
+
     return architectures
 
 

snapcraft/utils.py

@@ -127,6 +127,24 @@ def get_host_architecture():
     )
 
 
+def is_architecture_supported(architecture: str) -> bool:
+    """Check if an debian-syntax architecture is supported.
+
+    :param architecture: architecture to check
+
+    :returns: True if the architecture is supported by snapcraft.
+    """
+    return architecture in list(_ARCH_TRANSLATIONS_DEB_TO_PLATFORM)
+
+
+def get_supported_architectures() -> List[str]:
+    """Get a list of architectures supported by snapcraft.
+
+    :returns: A list of architectures.
+    """
+    return list(_ARCH_TRANSLATIONS_DEB_TO_PLATFORM.keys())
+
+
 def convert_architecture_deb_to_platform(architecture: str) -> str:
     """Convert an architecture from deb/snap syntax to platform syntax.
 

tests/unit/test_projects.py

@@ -1679,6 +1679,24 @@ def test_architecture_multiple_build_for_same_architecture_implicit(
             error.value
         )
 
+    @pytest.mark.parametrize(
+        "architectures",
+        [
+            "unknown",
+            {"build-on": ["unknown"]},
+            {"build-on": ["unknown"], "build-for": ["amd64"]},
+            {"build-on": ["amd64"], "build-for": ["unknown"]},
+        ],
+    )
+    def test_architecture_unsupported(self, architectures, project_yaml_data):
+        """Raise an error for unsupported architectures."""
+        data = project_yaml_data(architectures=[architectures])
+
+        with pytest.raises(errors.ProjectValidationError) as error:
+            Project.unmarshal(data)
+
+        assert "Architecture 'unknown' is not supported." in str(error.value)
+
     def test_project_get_build_on(self, project_yaml_data):
         """Test `get_build_on()` returns the build-on string."""
         data = project_yaml_data(

tests/unit/test_utils.py

@@ -478,6 +478,38 @@ def test_process_version_git(mocker):
     assert utils.process_version("git") == "1.2.3-dirty"
 
 
+###########################
+# Supported architectures #
+###########################
+
+
+@pytest.mark.parametrize("arch", utils.get_supported_architectures())
+def test_is_architecture_supported(arch):
+    """Supported architectures should return true."""
+    assert utils.is_architecture_supported(arch)
+
+
+def test_is_architecture_not_supported():
+    """Unsupported architectures should return false."""
+    assert not utils.is_architecture_supported("unknown")
+
+
+def get_supported_architectures():
+    """Validate list of supported architectures."""
+    supported_archs = utils.get_supported_architectures()
+
+    assert supported_archs == [
+        "arm64",
+        "armhf",
+        "i386",
+        "powerpc",
+        "ppc64el",
+        "amd64",
+        "s390x",
+        "riscv64",
+    ]
+
+
 #########################
 # Convert Architectures #
 #########################