feat(resolver): dispatch configured source resolvers

docs/concepts/resolver-architecture.rst

@@ -90,10 +90,16 @@ CLI commands interact with providers through a common
        Used when versions are already known, e.g. from a prior
        resolution or a settings-provided URL template.
 
+.. versionchanged:: 0.95.0
+   Packages with ``source:`` configuration now select their provider through
+   the configured source resolver.
+
 Per-package settings in YAML can select which provider to use and
-configure its parameters (index URL, tag pattern, etc.).  Override
-plugins can replace the provider entirely for a specific package via
-the ``get_resolver_provider`` hook.
+configure its parameters (index URL, tag pattern, etc.).  When a package
+has a ``source:`` resolver configured, that resolver creates the provider.
+Otherwise, override plugins can replace the provider for a specific package
+via the ``get_resolver_provider`` hook, after which the legacy resolver
+settings are used.
 
 Version Filtering Window
 -------------------------

src/fromager/packagesettings/_resolver.py

@@ -67,7 +67,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.BaseProvider:
         """Return a resolver provider for the given requirement."""
         raise NotImplementedError
@@ -198,7 +198,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.PyPIProvider:
         return resolver.PyPIProvider(
             include_sdists=True,
@@ -249,7 +249,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.PyPIProvider:
         return resolver.PyPIProvider(
             include_sdists=False,
@@ -322,7 +322,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.PyPIProvider:
         return resolver.PyPIProvider(
             include_sdists=True,
@@ -404,7 +404,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.PyPIProvider:
         download_url = f"git+{self.clone_url}@refs/tags/{self.tag}"
         return resolver.PyPIProvider(
@@ -510,7 +510,7 @@ def _github_provider(
         self,
         *,
         ctx: context.WorkContext,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
         override_download_url: str | None = None,
     ) -> resolver.GitHubTagProvider:
         if self.project_url.host != "github.com":
@@ -534,7 +534,7 @@ def _gitlab_provider(
         self,
         *,
         ctx: context.WorkContext,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
         override_download_url: str | None = None,
     ) -> resolver.GitLabTagProvider:
         if not self.project_url.path:
@@ -571,7 +571,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.GitHubTagProvider:
         return self._github_provider(
             ctx=ctx,
@@ -612,7 +612,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.GitHubTagProvider:
         return self._github_provider(
             ctx=ctx,
@@ -651,7 +651,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.GitLabTagProvider:
         return self._gitlab_provider(
             ctx=ctx,
@@ -692,7 +692,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.GitLabTagProvider:
         return self._gitlab_provider(
             ctx=ctx,
@@ -719,7 +719,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.BaseProvider:
         raise ValueError(f"package {req.name} is not available")
 
@@ -743,7 +743,7 @@ def resolver_provider(
         self,
         ctx: context.WorkContext,
         req: Requirement,
-        req_type: requirements_file.RequirementType,
+        req_type: requirements_file.RequirementType | None,
     ) -> resolver.BaseProvider:
         # TODO
         raise NotImplementedError("Hook resolver needs a hook")

src/fromager/resolver.py

@@ -157,6 +157,36 @@ def _has_equality_pin(req: Requirement) -> bool:
     return len(specs) == 1 and specs[0].operator == "==" and "*" not in specs[0].version
 
 
+def _effective_cooldown(
+    global_cooldown: Cooldown | None,
+    per_package_days: int | None,
+) -> Cooldown | None:
+    """Merge a per-package cooldown override with the global cooldown.
+
+    Args:
+        global_cooldown: The global cooldown from ``ctx.cooldown``.
+        per_package_days: Per-package override in days — ``None`` inherits
+            the global value, ``0`` disables cooldown, a positive integer
+            overrides it.
+
+    Returns:
+        The effective cooldown, or ``None`` if disabled.
+    """
+    if per_package_days is None:
+        return global_cooldown
+    if per_package_days == 0:
+        return None
+    bootstrap_time = (
+        global_cooldown.bootstrap_time
+        if global_cooldown is not None
+        else datetime.datetime.now(datetime.UTC)
+    )
+    return Cooldown(
+        min_age=datetime.timedelta(days=per_package_days),
+        bootstrap_time=bootstrap_time,
+    )
+
+
 def resolve_package_cooldown(
     ctx: context.WorkContext,
     req: Requirement,
@@ -178,22 +208,7 @@ def resolve_package_cooldown(
         return None
 
     per_package_days = ctx.package_build_info(req).resolver_min_release_age
-    global_cooldown = ctx.cooldown
-    if per_package_days is None:
-        return global_cooldown
-    if per_package_days == 0:
-        return None
-    # Per-package positive override: inherit bootstrap_time from global so all
-    # resolutions in a single run share the same fixed cutoff point.
-    bootstrap_time = (
-        global_cooldown.bootstrap_time
-        if global_cooldown is not None
-        else datetime.datetime.now(datetime.UTC)
-    )
-    return Cooldown(
-        min_age=datetime.timedelta(days=per_package_days),
-        bootstrap_time=bootstrap_time,
-    )
+    return _effective_cooldown(ctx.cooldown, per_package_days)
 
 
 def _compute_max_age_cutoff(

src/fromager/sources.py

@@ -116,8 +116,25 @@ def get_source_provider(
 
     Returns a provider configured according to the package's resolver settings
     (sdist/wheel inclusion, platform matching, server URL override).
+
+    Packages with a ``source:`` resolver use that resolver's provider
+    configuration. Packages without one retain the legacy override-hook and
+    ``resolver_dist`` behavior.
     """
     pbi = ctx.package_build_info(req)
+
+    source_resolver = pbi.source_resolver
+    if source_resolver is not None:
+        provider = source_resolver.resolver_provider(ctx, req, req_type)
+        if req_type == RequirementType.TOP_LEVEL and resolver._has_equality_pin(req):
+            provider.cooldown = None
+        else:
+            per_package_days = getattr(source_resolver, "min_release_age", None)
+            provider.cooldown = resolver._effective_cooldown(
+                ctx.cooldown, per_package_days
+            )
+        return provider
+
     override_sdist_server_url = pbi.resolver_sdist_server_url(sdist_server_url)
 
     provider = typing.cast(

tests/test_bootstrap_requirement_resolver.py

@@ -494,23 +494,32 @@ def test_resolve_auto_routes_to_source(
     mock_pbi.resolver_min_release_age = None
 
     with patch.object(tmp_context, "package_build_info", return_value=mock_pbi):
-        resolver = BootstrapRequirementResolver(tmp_context)
+        brr = BootstrapRequirementResolver(tmp_context)
 
         # Mock source resolution to return expected result (as list)
         mock_resolve.return_value = [
             ("https://files.pythonhosted.org/mypackage-2.0.tar.gz", Version("2.0"))
         ]
 
         # Call resolve with pre_built=None (should auto-detect)
-        results = resolver.resolve(
-            req=req,
-            req_type=RequirementType.INSTALL,
-            parent_req=None,
-            pre_built=None,
-        )
+        with patch(
+            "fromager.bootstrap_requirement_resolver.sources.get_source_provider"
+        ) as get_source_provider:
+            results = brr.resolve(
+                req=req,
+                req_type=RequirementType.INSTALL,
+                parent_req=None,
+                pre_built=None,
+            )
 
         # Verify resolution was called
         mock_resolve.assert_called_once()
+        get_source_provider.assert_called_once_with(
+            ctx=tmp_context,
+            req=req,
+            sdist_server_url="https://pypi.org/simple",
+            req_type=RequirementType.INSTALL,
+        )
         assert len(results) == 1
         url, version = results[0]
         assert url == "https://files.pythonhosted.org/mypackage-2.0.tar.gz"