Restore the uv extra, look for uv under sys.prefix

pyproject.toml

@@ -50,7 +50,7 @@ docs = [
   "sphinx-issues >= 3.0.0",
 ]
 test = [
-  "build[virtualenv]",
+  "build[uv, virtualenv]",
   "filelock >= 3",
   "pytest >= 6.2.4",
   "pytest-cov >= 2.12",
@@ -62,15 +62,18 @@ test = [
   'setuptools >= 56.0.0; python_version == "3.10"',
   'setuptools >= 56.0.0; python_version == "3.11"',
   'setuptools >= 67.8.0; python_version >= "3.12"',
-  "uv >= 0.1.15",
 ]
 typing = [
+  "build[uv]",
   "importlib-metadata >= 5.1",
   "mypy ~= 1.5.0",
   "tomli",
   "typing-extensions >= 3.7.4.3",
   "uv >= 0.1.15",
 ]
+uv = [
+  "uv >= 0.1.15",
+]
 virtualenv = [
   "virtualenv >= 20.0.35",
 ]

src/build/env.py

@@ -282,10 +282,19 @@ def create(self, path: str) -> None:
 
         self._env_path = path
 
-        uv_bin = shutil.which('uv')
+        # ``uv.find_uv_bin`` will look for uv in the user prefix if it can't
+        # find it under ``sys.prefix``, essentially potentially rearranging
+        # the user's $PATH.  We'll only look for uv under the prefix of
+        # the running interpreter for unactivated venvs then defer to $PATH.
+        uv_bin = shutil.which('uv', path=sysconfig.get_path('scripts'))
+
+        if not uv_bin:
+            uv_bin = shutil.which('uv')
+
         if not uv_bin:
             msg = 'uv executable missing'
             raise RuntimeError(msg)
+
         self._uv_bin = uv_bin
 
         if sys.implementation.name == 'pypy':

tests/test_env.py

@@ -6,6 +6,7 @@
 import subprocess
 import sys
 import sysconfig
+import typing
 
 from pathlib import Path
 from types import SimpleNamespace
@@ -64,6 +65,7 @@ def test_venv_executable_missing_post_creation(
     assert venv_create.call_count == 1
 
 
+@typing.no_type_check
 def test_isolated_env_abstract():
     with pytest.raises(TypeError):
         build.env.IsolatedEnv()