Use uv to install packages into venvs in regr_test.py

requirements-tests.txt

@@ -21,6 +21,7 @@ termcolor>=2.3
 tomli==2.0.1
 tomlkit==0.12.3
 typing_extensions>=4.9.0rc1
+uv
 
 # Type stubs used to type check our scripts.
 types-pyyaml>=6.0.12.7

tests/regr_test.py

@@ -148,13 +148,16 @@ def setup_testcase_dir(package: PackageInfo, tempdir: Path, verbosity: Verbosity
         shutil.copytree(Path("stubs", requirement), new_typeshed / "stubs" / requirement)
 
     if requirements.external_pkgs:
-        pip_exe = make_venv(tempdir / VENV_DIR).pip_exe
+        venv_location = str(tempdir / VENV_DIR)
+        subprocess.run(["uv", "venv", venv_location], check=True)
         # Use --no-cache-dir to avoid issues with concurrent read/writes to the cache
-        pip_command = [pip_exe, "install", get_mypy_req(), *requirements.external_pkgs, "--no-cache-dir"]
+        uv_command = ["uv", "pip", "install", get_mypy_req(), *requirements.external_pkgs, "--no-cache-dir"]
         if verbosity is Verbosity.VERBOSE:
-            verbose_log(f"{package.name}: Setting up venv in {tempdir / VENV_DIR}. {pip_command=}\n")
+            verbose_log(f"{package.name}: Setting up venv in {venv_location}. {uv_command=}\n")
         try:
-            subprocess.run(pip_command, check=True, capture_output=True, text=True)
+            subprocess.run(
+                uv_command, check=True, capture_output=True, text=True, env=os.environ | {"VIRTUAL_ENV": venv_location}
+            )
         except subprocess.CalledProcessError as e:
             _PRINT_QUEUE.put(f"{package.name}\n{e.stderr}")
             raise