docs: remove deprecated resolve_source hook

Remove the resolve_source plugin entry point and its documentation:
- Removed entry point from pyproject.toml
- Removed default_resolve_source from hooks.rst

This hook was replaced by the get_resolver_provider hook during the
resolver refactoring. Resolution now uses the provider pattern directly
instead of calling resolve_source as a plugin hook.

Fixes ReadTheDocs CI warning about missing default_resolve_source.

Co-Authored-By: Claude Sonnet 4.5 <[email protected]>
Signed-off-by: Rohan Devasthale <[email protected]>

Author: rd4398

docs/customization.md

@@ -90,7 +90,7 @@ source url can be provided directly in settings.yaml. Optionally the
 downloaded sdist can be renamed. Both the url and the destination filename
 support templating. The only supported template variable are:
 
-- `version` - it is replaced by the version returned by the `resolve_source`
+- `version` - it is replaced by the resolved version of the package
 - `canonicalized_name` - it is replaced by the canonicalized name of the
   package specified in the requirement, specifically it applies `canonicalize_name(req.nam)`
 

docs/reference/hooks.rst

@@ -191,27 +191,13 @@ Source hooks
 
 .. currentmodule:: fromager.sources
 
-.. autofromagerhook:: default_resolve_source
-
-    The ``resolve_source()`` function is responsible for resolving a
-    requirement and acquiring the source for that version of a
-    package. The default is to use pypi.org to resolve the requirement.
-
-    The arguments are the ``WorkContext``, the ``Requirement`` being
-    evaluated, and the URL to the sdist index.
-
-    The return value is ``Tuple[str, Version]`` where the first member is
-    the url from which the source can be downloaded and the second member
-    is the version of the resolved package.
-
 .. autofromagerhook:: default_download_source
 
     The ``download_source()`` function is responsible for downloading the
     source from a URL.
 
     The arguments are the ``WorkContext``, the ``Requirement`` being
-    evaluated, version of the package being downloaded, the URL
-    from which the source can be downloaded as returned by ``resolve_source``,
+    evaluated, version of the package being downloaded, the download URL,
     and the output directory in which the source should be downloaded.
 
     The return value should be a ``pathlib.Path`` file path to the downloaded source.

pyproject.toml

@@ -101,7 +101,6 @@ get_build_backend_dependencies = "fromager.dependencies:default_get_build_backen
 get_build_sdist_dependencies = "fromager.dependencies:default_get_build_sdist_dependencies"
 resolver_provider = "fromager.resolver:default_resolver_provider"
 download_source = "fromager.sources:default_download_source"
-resolve_source = "fromager.sources:default_resolve_source"
 build_sdist = "fromager.sources:default_build_sdist"
 build_wheel = "fromager.wheels:default_build_wheel"
 

src/fromager/bootstrap_requirement_resolver.py

@@ -9,10 +9,12 @@
 import logging
 import typing
 
+import pypi_simple.errors
+import resolvelib.resolvers
 from packaging.requirements import Requirement
 from packaging.version import Version
 
-from . import overrides, resolver
+from . import overrides, resolver, wheels
 from .dependency_graph import DependencyGraph
 from .requirements_file import RequirementType
 
@@ -151,14 +153,10 @@ def _resolve(
 
         if pre_built:
             # Resolve prebuilt wheel
-            # Get wheel server URLs
-            wheel_server_urls: list[str] = []
-            if pbi.wheel_server_url:
-                wheel_server_urls.append(pbi.wheel_server_url)
-            else:
-                if self.ctx.wheel_server_url:
-                    wheel_server_urls.append(self.ctx.wheel_server_url)
-                wheel_server_urls.append(resolver.PYPI_SERVER_URL)
+            # Get wheel server URLs (use PyPI as cache/fallback server)
+            wheel_server_urls = wheels.get_wheel_server_urls(
+                self.ctx, req, cache_wheel_server_url=resolver.PYPI_SERVER_URL
+            )
 
             # Try each wheel server until one succeeds
             for url in wheel_server_urls:
@@ -175,10 +173,20 @@ def _resolve(
                         req_type=req_type,
                         ignore_platform=False,
                     )
-                    results = resolver.resolve_from_provider(provider, req)
+                    results = resolver.find_all_matching_from_provider(provider, req)
                     if results:
                         return results
-                except Exception:
+                    else:
+                        logger.debug(
+                            f"{req.name}: no prebuilt wheel found on {url}, trying next server"
+                        )
+                except (
+                    resolvelib.resolvers.ResolverException,
+                    pypi_simple.errors.NoSuchProjectError,
+                ) as e:
+                    # Only catch expected "not found" exceptions - try next server
+                    # Let auth failures, network errors, and plugin bugs propagate
+                    logger.debug(f"{req.name}: no matching wheel on {url}: {e}")
                     continue
             # If we get here, no wheel server succeeded
             raise ValueError(
@@ -201,7 +209,7 @@ def _resolve(
                 req_type=req_type,
                 ignore_platform=pbi.resolver_ignore_platform,
             )
-            return resolver.resolve_from_provider(provider, req)
+            return resolver.find_all_matching_from_provider(provider, req)
 
     def get_cached_resolution(
         self,
@@ -369,8 +377,8 @@ def _resolve_from_version_source(
                 constraints=self.ctx.constraints,
                 use_resolver_cache=False,
             )
-            # resolve_from_provider now returns all matching candidates
-            return resolver.resolve_from_provider(provider, req)
+            # find_all_matching_from_provider now returns all matching candidates
+            return resolver.find_all_matching_from_provider(provider, req)
         except Exception as err:
             logger.debug(f"could not resolve {req} from {version_source}: {err}")
             return None

src/fromager/commands/list_overrides.py

@@ -77,7 +77,6 @@ def list_overrides(
                 "prebuilt_wheel",
                 # from overrides.py, found by searching for find_override_method
                 "download_source",
-                "resolve_source",
                 "get_resolver_provider",
                 "prepare_source",
                 "build_sdist",

src/fromager/resolver.py

@@ -103,7 +103,7 @@ def resolve(
         req_type=req_type,
         ignore_platform=ignore_platform,
     )
-    results = resolve_from_provider(provider, req)
+    results = find_all_matching_from_provider(provider, req)
     return results[0]
 
 
@@ -168,21 +168,37 @@ def ending(self, state: typing.Any) -> None:
         self._report("successfully resolved %r", self.req)
 
 
-def resolve_from_provider(
+def find_all_matching_from_provider(
     provider: BaseProvider, req: Requirement
 ) -> list[tuple[str, Version]]:
-    """Resolve requirement and return all matching candidates.
+    """Find all matching candidates from provider without full dependency resolution.
+
+    This function collects ALL candidates that match the requirement, rather than
+    performing full dependency resolution to find a single best candidate.
 
     Returns list of (url, version) tuples sorted by version (highest first).
+
+    IMPORTANT: This bypasses resolvelib's full resolver to collect all matching
+    candidates. This is safe ONLY because BaseProvider.get_dependencies() returns
+    an empty list (no transitive dependencies to resolve). The empty incompatibilities
+    dict means no version is ever excluded based on conflicts.
+
+    If get_dependencies() is ever extended to return actual dependencies, this
+    function must be revisited to use resolvelib's full resolution algorithm
+    (Resolver.resolve()) to properly handle dependency conflicts and backtracking.
     """
     # Get all matching candidates directly from provider
     # instead of using resolvelib's resolver which picks just one
     identifier = provider.identify(req)
     try:
+        # Bypass resolvelib's resolver to collect all matching candidates rather than
+        # just the single best one. This is safe because get_dependencies() returns []
+        # (no transitive deps to resolve). If get_dependencies() is ever extended,
+        # this must be revisited to use resolvelib's full resolution.
         candidates = provider.find_matches(
             identifier=identifier,
             requirements={identifier: [req]},
-            incompatibilities={},
+            incompatibilities={},  # Empty - safe only because no transitive deps
         )
     except resolvelib.resolvers.ResolverException as err:
         constraint = provider.constraints.get_constraint(req.name)
@@ -193,7 +209,8 @@ def resolve_from_provider(
         ) from err
 
     # Convert candidates to list of (url, version) tuples
-    # Candidates are already sorted by version (highest first)
+    # Candidates are sorted by version (highest first) by BaseProvider.find_matches()
+    # which calls sorted(candidates, key=attrgetter("version", "build_tag"), reverse=True)
     return [(candidate.url, candidate.version) for candidate in candidates]
 
 

src/fromager/sources.py

@@ -49,7 +49,6 @@ def get_source_type(ctx: context.WorkContext, req: Requirement) -> SourceType:
     pbi = ctx.package_build_info(req)
     if (
         overrides.find_override_method(req.name, "download_source")
-        or overrides.find_override_method(req.name, "resolve_source")
         or overrides.find_override_method(req.name, "get_resolver_provider")
         or pbi.download_source_url(resolve_template=False)
     ):
@@ -160,7 +159,7 @@ def resolve_source(
         )
 
         # Get all matching candidates from provider
-        results = resolver.resolve_from_provider(provider, req)
+        results = resolver.find_all_matching_from_provider(provider, req)
 
         # Return highest version (first in sorted list)
         url, version = results[0]

src/fromager/wheels.py

@@ -487,7 +487,7 @@ def resolve_prebuilt_wheel(
             )
 
             # Get all matching candidates from provider
-            results = resolver.resolve_from_provider(provider, req)
+            results = resolver.find_all_matching_from_provider(provider, req)
 
             if results:
                 # Return highest version (first in sorted list)

tests/test_bootstrap_requirement_resolver.py

@@ -448,7 +448,7 @@ def test_resolve_rejects_git_urls_for_source(tmp_context: WorkContext) -> None:
         )
 
 
-@patch("fromager.resolver.resolve_from_provider")
+@patch("fromager.resolver.find_all_matching_from_provider")
 def test_resolve_allows_git_urls_for_prebuilt(
     mock_resolve: MagicMock,
     tmp_context: WorkContext,
@@ -476,7 +476,7 @@ def test_resolve_allows_git_urls_for_prebuilt(
     assert version == Version("1.0")
 
 
-@patch("fromager.resolver.resolve_from_provider")
+@patch("fromager.resolver.find_all_matching_from_provider")
 def test_resolve_auto_routes_to_prebuilt(
     mock_resolve: MagicMock,
     tmp_context: WorkContext,
@@ -514,7 +514,7 @@ def test_resolve_auto_routes_to_prebuilt(
         assert version == Version("1.0")
 
 
-@patch("fromager.resolver.resolve_from_provider")
+@patch("fromager.resolver.find_all_matching_from_provider")
 def test_resolve_auto_routes_to_source(
     mock_resolve: MagicMock,
     tmp_context: WorkContext,
@@ -554,7 +554,7 @@ def test_resolve_auto_routes_to_source(
         assert version == Version("2.0")
 
 
-@patch("fromager.resolver.resolve_from_provider")
+@patch("fromager.resolver.find_all_matching_from_provider")
 def test_resolve_prebuilt_after_source_uses_separate_cache(
     mock_resolve: MagicMock,
     tmp_context: WorkContext,

tests/test_resolver.py

@@ -1213,7 +1213,9 @@ def test_custom_resolver_error_message_missing_tag() -> None:
         provider = resolver.GitHubTagProvider(organization="test-org", repo="test-repo")
 
         with pytest.raises(resolvelib.resolvers.ResolverException) as exc_info:
-            resolver.resolve_from_provider(provider, Requirement("test-package==1.0.0"))
+            resolver.find_all_matching_from_provider(
+                provider, Requirement("test-package==1.0.0")
+            )
 
         error_message = str(exc_info.value)
         assert (
@@ -1249,7 +1251,9 @@ def custom_resolver_provider(
         provider = custom_resolver_provider()
 
         with pytest.raises(resolvelib.resolvers.ResolverException) as exc_info:
-            resolver.resolve_from_provider(provider, Requirement("test-package==1.0.0"))
+            resolver.find_all_matching_from_provider(
+                provider, Requirement("test-package==1.0.0")
+            )
 
         error_message = str(exc_info.value)
         # After fix for issue #858, the error message should indicate that a GitHub resolver was used