feat(resolver): add versionmap-git source resolver

Add `VersionMapGitResolver` config model for the `versionmap-git`
provider from the new-resolver-config proposal. Maps version numbers
to git refs (commit SHAs or ref paths) with a separate `clone_url`,
replacing the need for handwritten Python plugins.

- Add `VersionMapGitResolver` pydantic model with `clone_url`,
  `build_sdist`, and `versionmap` fields
- Register in `SourceResolver` discriminated union
- Add to config reference docs
- Add tests for config parsing, provider output, and validation

Closes: AIPCC-17610
Co-Authored-By: Claude <claude@anthropic.com>
Signed-off-by: Josef Skladanka <jskladan@redhat.com>

Author: Josef Skladanka

docs/reference/config-reference.rst

@@ -41,6 +41,8 @@ Source Resolver
 .. autopydantic_model:: PyPIGitResolver
    :inherited-members: AbstractPyPIResolver, CooldownMixin
 
+.. autopydantic_model:: VersionMapGitResolver
+
 .. autopydantic_model:: GitHubTagDownloadResolver
    :inherited-members: AbstractGitSourceResolver, CooldownMixin
 

src/fromager/packagesettings/__init__.py

@@ -25,6 +25,7 @@
     PyPIGitResolver,
     PyPIPrebuiltResolver,
     PyPISDistResolver,
+    VersionMapGitResolver,
     pep440_tag_matcher,
 )
 from ._settings import Settings, SettingsFile
@@ -82,6 +83,7 @@
     "Variant",
     "VariantChangelog",
     "VariantInfo",
+    "VersionMapGitResolver",
     "default_update_extra_environ",
     "get_extra_environ",
     "pep440_tag_matcher",

src/fromager/packagesettings/_resolver.py

@@ -482,6 +482,63 @@ def resolver_provider(
         )
 
 
+class VersionMapGitResolver(AbstractResolver):
+    """Resolve version from a version map, build sdist from git clone.
+
+    The ``versionmap-git`` provider maps known version numbers to known git
+    refs (commit SHAs or ref paths such as ``refs/tags/1.1``).  It clones a
+    git repo at the configured ref and builds an sdist with PEP 517.
+
+    Example::
+
+       provider: versionmap-git
+       clone_url: https://git.test/project/repo.git
+       build_sdist: pep517
+       versionmap:
+         '1.0': abad1dea
+         '1.1': refs/tags/1.1
+
+    .. versionadded:: 0.79.0
+    """
+
+    provider: typing.Literal["versionmap-git"]
+
+    clone_url: pydantic.AnyUrl
+    """Git clone URL (``https`` or ``ssh`` scheme)."""
+
+    build_sdist: BuildSDist = BuildSDist.pep517
+    """Source distribution build method."""
+
+    versionmap: dict[str, str]
+    """Mapping of version strings to git refs."""
+
+    @pydantic.field_validator("clone_url", mode="after")
+    @classmethod
+    def validate_clone_url(cls, value: pydantic.AnyUrl) -> pydantic.AnyUrl:
+        if value.scheme not in {"https", "ssh"}:
+            raise ValueError(f"invalid scheme in url {value}")
+        if not value.path:
+            raise ValueError(f"url {value} has an empty path")
+        return value
+
+    def resolver_provider(
+        self, ctx: context.WorkContext, req_type: requirements_file.RequirementType
+    ) -> resolver.VersionMapProvider:
+        from ..versionmap import VersionMap
+
+        clone_url = str(self.clone_url)
+        url_map = {
+            ver: f"git+{clone_url}@{ref}" for ver, ref in self.versionmap.items()
+        }
+        version_map = VersionMap(url_map)  # type: ignore[arg-type]
+        return resolver.VersionMapProvider(
+            version_map=version_map,
+            package_name=None,
+            constraints=ctx.constraints,
+            req_type=req_type,
+        )
+
+
 class NotAvailableResolver(AbstractResolver):
     """Prevent resolve and download"""
 
@@ -510,6 +567,7 @@ def resolver_provider(
     | PyPIPrebuiltResolver
     | PyPIDownloadResolver
     | PyPIGitResolver
+    | VersionMapGitResolver
     | GitHubTagCloneResolver
     | GitHubTagDownloadResolver
     | GitLabTagCloneResolver

tests/test_packagesettings_resolver.py

@@ -25,6 +25,7 @@
     PyPIPrebuiltResolver,
     PyPISDistResolver,
     SourceResolver,
+    VersionMapGitResolver,
 )
 from fromager.packagesettings._typedefs import MODEL_CONFIG
 from fromager.requirements_file import RequirementType
@@ -426,6 +427,50 @@ def test_resolver_provider(self, tmp_context: WorkContext) -> None:
 # -- Special resolvers --------------------------------------------------------
 
 
+class TestVersionMapGitResolver:
+    YAML = """\
+        source:
+          provider: versionmap-git
+          clone_url: https://git.test/project/repo.git
+          build_sdist: pep517
+          versionmap:
+            '1.0': abad1dea
+            '1.1': refs/tags/1.1
+    """
+
+    def test_parse(self) -> None:
+        r = _parse(self.YAML)
+        assert isinstance(r, VersionMapGitResolver)
+        assert r.provider == "versionmap-git"
+        assert str(r.clone_url) == "https://git.test/project/repo.git"
+        assert r.build_sdist == BuildSDist.pep517
+        assert r.versionmap == {"1.0": "abad1dea", "1.1": "refs/tags/1.1"}
+
+    def test_resolver_provider(self, tmp_context: WorkContext) -> None:
+        r = _parse(self.YAML)
+        p = r.resolver_provider(tmp_context, _REQ_TYPE)
+        assert isinstance(p, resolver.VersionMapProvider)
+        clone_url = "https://git.test/project/repo.git"
+        assert p.version_map["1.0"] == f"git+{clone_url}@abad1dea"
+        assert p.version_map["1.1"] == f"git+{clone_url}@refs/tags/1.1"
+
+    def test_clone_url_rejects_http(self) -> None:
+        with pytest.raises(pydantic.ValidationError):
+            VersionMapGitResolver(
+                provider="versionmap-git",
+                clone_url="http://git.test/project/repo.git",  # type: ignore[arg-type]
+                versionmap={"1.0": "abc123"},
+            )
+
+    def test_clone_url_rejects_empty_path(self) -> None:
+        with pytest.raises(pydantic.ValidationError):
+            VersionMapGitResolver(
+                provider="versionmap-git",
+                clone_url="https://git.test",  # type: ignore[arg-type]
+                versionmap={"1.0": "abc123"},
+            )
+
+
 class TestNotAvailableResolver:
     YAML = """\
         source:

tests/test_resolver.py

@@ -920,6 +920,64 @@ def test_resolve_versionmap_no_match() -> None:
         rslvr.resolve([Requirement("testpkg>=2.0")])
 
 
+def test_resolve_versionmap_git() -> None:
+    from fromager.versionmap import VersionMap
+
+    clone_url = "https://git.test/project/repo.git"
+    version_map = VersionMap(
+        {
+            "1.0": f"git+{clone_url}@abad1dea",
+            "1.1": f"git+{clone_url}@refs/tags/1.1",
+            "1.2": f"git+{clone_url}@d3adb33f",
+        }
+    )
+
+    provider = resolver.VersionMapProvider(
+        version_map=version_map,
+        package_name="testpkg",
+    )
+    reporter: resolvelib.BaseReporter = resolvelib.BaseReporter()
+    rslvr = resolvelib.Resolver(provider, reporter)
+
+    result = rslvr.resolve([Requirement("testpkg")])
+    assert "testpkg" in result.mapping
+
+    candidate = result.mapping["testpkg"]
+    assert str(candidate.version) == "1.2"
+    assert candidate.url == f"git+{clone_url}@d3adb33f"
+
+
+def test_resolve_versionmap_git_with_constraint() -> None:
+    from fromager.versionmap import VersionMap
+
+    clone_url = "https://git.test/project/repo.git"
+    version_map = VersionMap(
+        {
+            "1.0": f"git+{clone_url}@abad1dea",
+            "1.1": f"git+{clone_url}@refs/tags/1.1",
+            "1.2": f"git+{clone_url}@d3adb33f",
+        }
+    )
+
+    c = constraints.Constraints()
+    c.add_constraint("testpkg<1.2")
+
+    provider = resolver.VersionMapProvider(
+        version_map=version_map,
+        package_name="testpkg",
+        constraints=c,
+    )
+    reporter: resolvelib.BaseReporter = resolvelib.BaseReporter()
+    rslvr = resolvelib.Resolver(provider, reporter)
+
+    result = rslvr.resolve([Requirement("testpkg")])
+    assert "testpkg" in result.mapping
+
+    candidate = result.mapping["testpkg"]
+    assert str(candidate.version) == "1.1"
+    assert candidate.url == f"git+{clone_url}@refs/tags/1.1"
+
+
 _gitlab_submodlib_repo_response = """
 [
   {