Warn on unresolvable force-includes and pch_defines-less sloppiness, vary the unreadable marker

tests/unit_tests/build_helpers/test_idedata.py

@@ -117,6 +117,27 @@ def test_parse_entry_keeps_search_chain_force_include(tmp_path: Path) -> None:
     assert cxx_flags[cxx_flags.index("-include") + 1] == "Arduino.h"
 
 
+def test_parse_entry_warns_on_vanished_force_include(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A build-dir force-include deleted by clean_build must leave a trail;
+    a name resolvable via the -I chain must not warn."""
+    inc = tmp_path / "inc"
+    inc.mkdir()
+    (inc / "Arduino.h").write_text("")
+    entry = _entry(
+        str(tmp_path),
+        f"{tmp_path}/src/esphome/x.cpp",
+        f"g++ -I{inc} -include Arduino.h -include esphome_pch.h -c x.cpp",
+    )
+
+    _, _, _, cxx_flags = idedata.parse_entry(entry)
+
+    assert "Arduino.h" in cxx_flags
+    assert "esphome_pch.h" in caplog.text
+    assert "Arduino.h" not in caplog.text
+
+
 def test_parse_entry_drops_trailing_force_include(
     tmp_path: Path, caplog: pytest.LogCaptureFixture
 ) -> None:

tests/unit_tests/build_helpers/test_pch.py

@@ -45,11 +45,22 @@ def test_ccache_pch_env_disabled() -> None:
         assert pch.ccache_pch_env() == {}
 
 
-def test_ccache_pch_env_respects_user_values() -> None:
+def test_ccache_pch_env_respects_user_values(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """A user CCACHE_SLOPPINESS wins, but one without pch_defines silently
+    stops ccache from caching pch consumers, so it must warn."""
     with patch.dict(os.environ, {"CCACHE_SLOPPINESS": "locale"}, clear=True):
         env = pch.ccache_pch_env()
     assert "CCACHE_SLOPPINESS" not in env
     assert env["CCACHE_PCH_EXTSUM"] == "true"
+    assert "lacks pch_defines" in caplog.text
+    caplog.clear()
+    with patch.dict(
+        os.environ, {"CCACHE_SLOPPINESS": "pch_defines,locale"}, clear=True
+    ):
+        pch.ccache_pch_env()
+    assert "lacks pch_defines" not in caplog.text
 
 
 def test_pch_header_text_preserves_order() -> None:
@@ -118,7 +129,9 @@ def test_include_closure_marks_unreadable(
         closure = pch._include_closure(tmp_path, ["a.h"])
     finally:
         locked.chmod(0o644)
-    assert closure["locked.h"] == b"<unreadable>"
+    # stat still works, so the marker varies with mtime/size and a later
+    # edit to the unreadable file still shifts the digest
+    assert closure["locked.h"].startswith(b"<unreadable:")
     assert "Could not read locked.h" in caplog.text