Remove UV_NO_CACHE=1

src/pyhc_actions/env_compat/uv_resolver.py

@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-import os
 import re
 import shutil
 import subprocess
@@ -385,13 +384,14 @@ def _report_error(
         if temp_constraints:
             command.extend(["-c", temp_constraints])
 
+        # We used to force UV_NO_CACHE=1 here for fully cold resolves, but removed that
+        # override to improve env-compat performance across repeated extras checks.
         result = subprocess.run(
             command,
             capture_output=True,
             text=True,
             # Handle both directory paths (setup.py) and file paths (pyproject.toml)
             cwd=pyproject_path if pyproject_path.is_dir() else pyproject_path.parent,
-            env={**os.environ, "UV_NO_CACHE": "1"},
         )
 
         if result.returncode == 0:

tests/test_compat_checker.py

@@ -480,6 +480,43 @@ def fake_run(cmd, *args, **kwargs):
         assert "--python-version" in captured["cmd"]
         assert "3.12" in captured["cmd"]
 
+    def test_uv_compile_does_not_force_no_cache(self, tmp_path, monkeypatch):
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text(
+            """
+[project]
+name = "demo"
+"""
+        )
+
+        captured: dict[str, object] = {}
+
+        class DummyResult:
+            returncode = 0
+            stdout = ""
+            stderr = ""
+
+        def fake_run(cmd, *args, **kwargs):
+            captured["cmd"] = cmd
+            captured["env"] = kwargs.get("env")
+            return DummyResult()
+
+        monkeypatch.setattr("pyhc_actions.env_compat.uv_resolver.find_uv", lambda: "/usr/bin/uv")
+        monkeypatch.setattr("pyhc_actions.env_compat.uv_resolver.subprocess.run", fake_run)
+
+        reporter = Reporter(title="Test", output=StringIO(), github_actions=False)
+        ok, _conflicts = check_compatibility(
+            pyproject_path=pyproject,
+            pyhc_packages=["numpy>=1.20"],
+            pyhc_constraints=[],
+            pyhc_python="3.12.0",
+            reporter=reporter,
+        )
+
+        assert ok is True
+        if isinstance(captured["env"], dict):
+            assert captured["env"].get("UV_NO_CACHE") != "1"
+
     def test_excludes_same_package_when_pyhc_entry_has_extras(self, tmp_path, monkeypatch):
         pyproject = tmp_path / "pyproject.toml"
         pyproject.write_text(