Do not resolve heavy extras that are not requested

src/poetry/puzzle/provider.py

@@ -248,8 +248,23 @@ def search_for_installed_packages(
         )
         return packages
 
-    def search_for_direct_origin_dependency(self, dependency: Dependency) -> Package:
+    def _get_from_deferred_cache(self, dependency: Dependency) -> Package | None:
         package = self._deferred_cache.get(dependency)
+        if package is None:
+            return None
+
+        if dependency.is_vcs():
+            dependency._source_reference = package.source_reference
+            dependency._source_resolved_reference = package.source_resolved_reference
+            dependency._source_subdirectory = package.source_subdirectory
+
+        dependency._constraint = package.version
+        dependency._pretty_constraint = package.version.text
+
+        return package
+
+    def search_for_direct_origin_dependency(self, dependency: Dependency) -> Package:
+        package = self._get_from_deferred_cache(dependency)
         if package is not None:
             pass
 
@@ -577,6 +592,19 @@ def complete_package(
         else:
             requires = package.requires
 
+        optional_dependencies: list[str] = []
+
+        # If some extras/features were required, we need to
+        # add a special dependency representing the base package
+        # to the current package
+        if dependency.extras:
+            for extra in dependency.extras:
+                extra = safe_extra(extra)
+                if extra not in package.extras:
+                    continue
+
+                optional_dependencies += [d.name for d in package.extras[extra]]
+
         if self._load_deferred:
             # Retrieving constraints for deferred dependencies
             for r in requires:
@@ -587,22 +615,30 @@ def complete_package(
                     # do not analyze it again: nothing could have changed.
                     if locked is not None and locked.package.is_same_package_as(r):
                         continue
+
+                    # If there is an optional dependency and it's not requested,
+                    # do not try resolving it.
+                    # Saves time when dep is a large Git repository for example.
+                    if (
+                        not package.is_root()
+                        and r.is_optional()
+                        and r.name not in optional_dependencies
+                    ):
+                        # When we have foo[extra] dependency, we will later consider
+                        # foo (w/o extras), at that moment this code will fire
+                        # and skip `r`. Update r with version and reference if it was
+                        # resolved on the previous step.
+                        _ = self._get_from_deferred_cache(r)
+                        continue
+
                     self.search_for_direct_origin_dependency(r)
 
-        optional_dependencies = []
-        _dependencies = []
+        _dependencies: list[Dependency] = []
 
         # If some extras/features were required, we need to
         # add a special dependency representing the base package
         # to the current package
         if dependency.extras:
-            for extra in dependency.extras:
-                extra = safe_extra(extra)
-                if extra not in package.extras:
-                    continue
-
-                optional_dependencies += [d.name for d in package.extras[extra]]
-
             dependency_package = dependency_package.with_features(
                 list(dependency.extras)
             )