fix: don't treat bad sdist metadata as fatal error

src/fromager/dependencies.py

@@ -33,6 +33,9 @@
 BUILD_SDIST_REQ_FILE_NAME = "build-sdist-requirements.txt"
 INSTALL_REQ_FILE_NAME = "requirements.txt"
 
+# marker for Fromager's stub PKG-INFO
+STUB_PKG_INFO_SUMMARY = "Fromage stub PKG-INFO"
+
 
 def get_build_system_dependencies(
     *,
@@ -314,14 +317,28 @@ def default_get_install_dependencies_of_sdist(
         config_settings=config_settings,
         validate=True,
     )
-    validate_dist_name_version(
-        req=req,
-        version=version,
-        what="sdist metadata",
-        # Metadata name is a non-normalized string
-        dist_name=canonicalize_name(metadata.name),
-        dist_version=metadata.version,
-    )
+    if metadata.summary is None or STUB_PKG_INFO_SUMMARY not in metadata.summary:
+        # Do not attempt to validate stub metadata. Version may be incorrect.
+        # Treat other validation errors as non-fatal errors.
+        try:
+            validate_dist_name_version(
+                req=req,
+                version=version,
+                what="sdist metadata",
+                # Metadata name is a non-normalized string
+                dist_name=canonicalize_name(metadata.name),
+                dist_version=metadata.version,
+            )
+        except Exception as e:
+            logger.error(
+                "metadata for %s==%s in %r failed to validate: %s",
+                req.name,
+                version,
+                sdist_root_dir,
+                e,
+            )
+    else:
+        logger.debug("Fromager stub metadata detected, not validating name and version")
     if not metadata.requires_dist:
         return set()
     return set(metadata.requires_dist)

src/fromager/sources.py

@@ -692,7 +692,7 @@ def pep517_build_sdist(
 Metadata-Version: 1.0
 Name: {name}
 Version: {version}
-Summary: Fromage stub PKG-INFO
+Summary: {summary}
 """
 
 
@@ -726,6 +726,7 @@ def ensure_pkg_info(
                 PKG_INFO_CONTENT.format(
                     name=req.name,
                     version=str(version),
+                    summary=dependencies.STUB_PKG_INFO_SUMMARY,
                 )
             )
             had_pkg_info = False

tests/test_dependencies.py

@@ -217,6 +217,7 @@ def test_default_get_install_dependencies_of_sdist(
     m_pep517_metadata_of_sdist: Mock,
     tmp_context: context.WorkContext,
     tmp_path: pathlib.Path,
+    caplog: pytest.LogCaptureFixture,
 ) -> None:
     req = Requirement("huggingface-hub")
     version = Version("1.2.3")
@@ -245,6 +246,34 @@ def test_default_get_install_dependencies_of_sdist(
     )
     assert requirements == {Requirement("filelock"), Requirement("requests")}
 
+    # bad metadata (version mismatch) is treated as non-fatal error
+    metadata_txt = textwrap.dedent(
+        """\
+        Metadata-Version: 2.3
+        Name: HuggingFace_Hub
+        Version: 1.2a0
+        Requires-Dist: filelock
+        Requires-Dist: requests
+        """
+    )
+    metadata = Metadata.from_email(metadata_txt)
+    m_pep517_metadata_of_sdist.return_value = metadata
+    requirements = dependencies.default_get_install_dependencies_of_sdist(
+        ctx=tmp_context,
+        req=req,
+        version=version,
+        sdist_root_dir=tmp_path,
+        build_env=Mock(),
+        extra_environ={},
+        build_dir=tmp_path,
+        config_settings={},
+    )
+    assert requirements == {Requirement("filelock"), Requirement("requests")}
+    assert (
+        "sdist metadata '1.2a0' does not match public version '1.2.3'"
+        in caplog.messages[-1]
+    )
+
 
 @pytest.mark.parametrize(
     "req_str,version_str,dist_name_str,dist_version_str,exc",