From 9f2e610540337bb6c1cdf42adfec217d5a37f6c8 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 20 Apr 2025 13:22:48 -0400
Subject: [PATCH] In _EditableFinder, allow (one) namespace package to be found
 in a simple package.

---
 setuptools/command/editable_wheel.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/setuptools/command/editable_wheel.py b/setuptools/command/editable_wheel.py
index 1a544ec258..3a247ce4ff 100644
--- a/setuptools/command/editable_wheel.py
+++ b/setuptools/command/editable_wheel.py
@@ -836,6 +836,11 @@ def _find_spec(cls, fullname: str, candidate_path: Path) -> ModuleSpec | None:
         for candidate in chain([init], candidates):
             if candidate.exists():
                 return spec_from_file_location(fullname, candidate)
+        if candidate_path.is_dir():
+            # treat it like a PEP 420 namespace package
+            spec = ModuleSpec(fullname, None, is_package=True)
+            spec.submodule_search_locations = [str(candidate_path)]
+            return spec
         return None