Close the native CI trigger gap and log the remaining silent library skips

tests/script/test_determine_jobs.py

@@ -3083,6 +3083,9 @@ def test_esp8266_native_components_full_list_on_infra_change() -> None:
         # Shared modules the native build depends on
         ["esphome/espidf/idedata.py"],
         ["esphome/platformio/library.py"],
+        # Top-level esphome/*.py modules the backend imports directly
+        ["esphome/framework_helpers.py"],
+        ["esphome/writer.py"],
     ):
         with (
             patch.object(determine_jobs, "changed_files", return_value=changed),

tests/unit_tests/build_gen/test_arduino8266.py

@@ -11,6 +11,7 @@ PlatformIO toolchain produces for the same configuration.
 from __future__ import annotations
 
 from collections.abc import Generator
+import logging
 from pathlib import Path
 from unittest.mock import MagicMock, patch
 
@@ -454,7 +455,9 @@ def test_generate_ld_scripts_testing_mode(tmp_path: Path) -> None:
     assert "len = 0x2000000" in patched
 
 
-def test_write_project_libraries_and_variant(tmp_path: Path) -> None:
+def test_write_project_libraries_and_variant(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
     from esphome.arduino8266.component import ArduinoLibrary
 
     paths = _make_framework(tmp_path)
@@ -477,14 +480,17 @@ def test_write_project_libraries_and_variant(tmp_path: Path) -> None:
     )
     _set_flags("-DPIO_FRAMEWORK_ARDUINO_ENABLE_EXCEPTIONS")
 
-    content = _write_ninja(
-        paths, libraries=[library, headers_only], ccache="/cc/ccache"
-    )
+    with caplog.at_level(logging.DEBUG, logger="esphome.build_gen.arduino8266"):
+        content = _write_ninja(
+            paths, libraries=[library, headers_only], ccache="/cc/ccache"
+        )
 
     assert "build libFrameworkArduinoVariant.a: ar" in content
     assert "build libMyLib.a: ar" in content
-    # A headers-only library contributes includes but no archive
+    # A headers-only library contributes includes but no archive, with a
+    # debug log distinguishing it from a resolution failure
     assert "libHeadersOnly.a" not in content
+    assert "Library HeadersOnly has no source files" in caplog.text
     assert "  flags = -DMYLIB=1" in content
     assert "-lalgobsec" in content
     # Library link flags reach the firmware link line; .cc compiles as C++

tests/unit_tests/test_arduino8266_component.py

@@ -84,6 +84,18 @@ def test_library_info_flags_parsing(tmp_path: Path) -> None:
     assert lib.link_flags == ["-Wl,--wrap=malloc"]
 
 
+def test_library_info_missing_link_dir_warns(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    read_path = tmp_path / "lib"
+    read_path.mkdir()
+    data = {"build": {"flags": ["-Lmissing_blobs"]}}
+    lib = component._library_info("x", read_path, data)
+    assert "declares library dir missing_blobs which does not exist" in caplog.text
+    # Kept anyway: the linker ignores missing -L dirs
+    assert lib.link_dirs == [(read_path / "missing_blobs").resolve()]
+
+
 def test_library_info_no_src_dir(tmp_path: Path) -> None:
     read_path = tmp_path / "empty"
     read_path.mkdir()