Normalize case before hashing so that the generated venv name is independent of case on Windows

src/poetry/utils/env.py

@@ -1072,7 +1072,8 @@ class EnvManager:
     def generate_env_name(cls, name: str, cwd: str) -> str:
         name = name.lower()
         sanitized_name = re.sub(r'[ $`!*@"\\\r\n\t]', "_", name)[:42]
-        h = hashlib.sha256(encode(cwd)).digest()
+        normalized_cwd = os.path.normcase(cwd)
+        h = hashlib.sha256(encode(normalized_cwd)).digest()
         h = base64.urlsafe_b64encode(h).decode()[:8]
 
         return f"{sanitized_name}-{h}"

tests/utils/test_env.py

@@ -1120,3 +1120,12 @@ def test_create_venv_accepts_fallback_version_w_nonzero_patchlevel(
         with_setuptools=True,
         with_wheel=True,
     )
+
+
+def test_generate_env_name_ignores_case_for_case_insensitive_fs(tmp_dir):
+    venv_name1 = EnvManager.generate_env_name("simple-project", "MyDiR")
+    venv_name2 = EnvManager.generate_env_name("simple-project", "mYdIr")
+    if sys.platform == "win32":
+        assert venv_name1 == venv_name2
+    else:
+        assert venv_name1 != venv_name2