Diagnostic error on pip uninstall of invalid package

src/pip/_internal/exceptions.py

@@ -22,10 +22,12 @@
 if TYPE_CHECKING:
     from hashlib import _Hash
 
+    from pip._vendor.packaging.requirements import InvalidRequirement
     from pip._vendor.requests.models import Request, Response
 
     from pip._internal.metadata import BaseDistribution
     from pip._internal.req.req_install import InstallRequirement
+    from pip._internal.resolution.resolvelib.candidates import AlreadyInstalledCandidate
 
 logger = logging.getLogger(__name__)
 
@@ -775,3 +777,21 @@ def __init__(self, *, distribution: "BaseDistribution") -> None:
             ),
             hint_stmt=None,
         )
+
+class InvalidInstalledPackage(DiagnosticPipError):
+    reference = "invalid-installed-package"
+
+    def __init__(
+            self,
+            *,
+            package: "AlreadyInstalledCandidate",
+            invalid_req_exc: "InvalidRequirement",
+        ) -> None:
+        super().__init__(
+            message=Text(
+                f"Cannot uninstall {package} because it has an invalid requirement:\n"
+                f"{invalid_req_exc.args[0]}."
+                ),
+            context="Since pip 24.1+ invalid requirements can not be read by pip.",
+            hint_stmt="Please use 'pip<24.1' if you need to uninstall this package.",
+        )

src/pip/_internal/resolution/resolvelib/candidates.py

@@ -9,6 +9,7 @@
 from pip._internal.exceptions import (
     HashError,
     InstallationSubprocessError,
+    InvalidInstalledPackage,
     MetadataInconsistent,
     MetadataInvalid,
 )
@@ -398,8 +399,12 @@ def format_for_error(self) -> str:
     def iter_dependencies(self, with_requires: bool) -> Iterable[Optional[Requirement]]:
         if not with_requires:
             return
-        for r in self.dist.iter_dependencies():
-            yield from self._factory.make_requirements_from_spec(str(r), self._ireq)
+
+        try:
+            for r in self.dist.iter_dependencies():
+                yield from self._factory.make_requirements_from_spec(str(r), self._ireq)
+        except InvalidRequirement as exc:
+            raise InvalidInstalledPackage(package=self, invalid_req_exc=exc) from None
 
     def get_install_requirement(self) -> Optional[InstallRequirement]:
         return None