[WIP] hack

src/pip/_internal/distributions/sdist.py

@@ -1,6 +1,8 @@
 import logging
 from typing import Iterable, Set, Tuple
 
+from pip._vendor.pep517.wrappers import HookMissing
+
 from pip._internal.build_env import BuildEnvironment
 from pip._internal.distributions.base import AbstractDistribution
 from pip._internal.exceptions import InstallationError
@@ -42,7 +44,10 @@ def _setup_isolation(self, finder: PackageFinder) -> None:
         # This must be done in a second pass, as the pyproject.toml
         # dependencies must be installed before we can call the backend.
         if self.req.editable and self.req.permit_editable_wheels:
-            build_reqs = self._get_build_requires_editable()
+            try:
+                build_reqs = self._get_build_requires_editable()
+            except HookMissing:
+                build_reqs = self._get_build_requires_wheel()
         else:
             build_reqs = self._get_build_requires_wheel()
         self._install_build_reqs(finder, build_reqs)

src/pip/_vendor/pep517/in_process/_in_process.py

@@ -126,7 +126,7 @@ def get_requires_for_build_editable(config_settings):
     try:
         hook = backend.get_requires_for_build_editable
     except AttributeError:
-        return []
+        raise HookMissing()
     else:
         return hook(config_settings)