diff --git a/esphome/arduino/library.py b/esphome/arduino/library.py
index f699d79704..45a89784e5 100644
--- a/esphome/arduino/library.py
+++ b/esphome/arduino/library.py
@@ -35,6 +35,7 @@ from esphome.platformio.library import (
     IncompatiblePlatform,
     InvalidLibrary,
     LibraryBackend,
+    _node_key,
     check_library_data,
     collect_filtered_files,
     convert_libraries,
@@ -71,7 +72,11 @@ class ArduinoLibrary:
 
 def _library_info(name: str, read_path: Path, data: dict) -> ArduinoLibrary:
     """Resolve one library's sources, include dirs, and flags (PIO semantics)."""
-    build = data.get("build", {})
+    build = data.get("build", {}) if isinstance(data, dict) else None
+    if not isinstance(build, dict):
+        # A bare json.load imposes no shape; name the library instead of an
+        # AttributeError deep in a traceback
+        raise EsphomeError(f"Library {name} has a malformed manifest")
 
     # PIO's source-dir resolution: manifest srcDir, else src/Src, else the root
     if "srcDir" in build:
@@ -177,6 +182,15 @@ def _bundled_library(framework_path: Path, name: str) -> ArduinoLibrary:
     else:
         manifest = lib_dir / "library.properties"
         data = parse_library_properties(manifest) if manifest.is_file() else {}
+    if isinstance(data, dict) and data.get("dependencies"):
+        # The dependency walk never runs for bundled libraries (a no-op for
+        # the ESP8266 core, whose bundled manifests declare none); on a core
+        # where one does, the skip must be visible before link errors
+        _LOGGER.warning(
+            "Bundled library %s declares dependencies, which are not "
+            "resolved automatically; add them with add_library() if needed",
+            name,
+        )
     return _library_info(name, lib_dir, data)
 
 
@@ -309,8 +323,15 @@ def resolve_libraries(
             # A requested library the converter dropped would otherwise
             # surface only as link errors far from the cause; name the
             # requests that went missing, not just the survivors
-            resolved_names = {c.name for c in resolved}
-            dropped = [str(lib) for lib in external if lib.name not in resolved_names]
+            # ConvertedLibrary.name is canonical (bare "pngle" resolves to
+            # "bitbank2__pngle"); diff the request-side node keys instead
+            resolved_keys = {c.node_key or c.name for c in resolved}
+            dropped = [
+                str(lib)
+                for lib in external
+                if _node_key(lib.name, lib.version, lib.repository)[0]
+                not in resolved_keys
+            ]
             _LOGGER.warning(
                 "%d of %d requested libraries were not resolved (missing: %s)",
                 len(external) - len(resolved),
diff --git a/esphome/platformio/library.py b/esphome/platformio/library.py
index 34c7a272cc..643a020df8 100644
--- a/esphome/platformio/library.py
+++ b/esphome/platformio/library.py
@@ -229,6 +229,10 @@ class ConvertedLibrary:
         self.name = name
         self.version = version
         self.source = source
+        # The request-side _node_key this component resolved from; the
+        # canonical name can differ (bare "pngle" -> "bitbank2__pngle"), so
+        # callers diff requests against this, not against name
+        self.node_key: str | None = None
         self.data = {}
         self.dependencies: list[ConvertedLibrary] = []
         self._path: Path | None = None
@@ -891,6 +895,7 @@ def convert_libraries(
             component = ConvertedLibrary(
                 _owner_pkgname_to_name(owner, name), version, URLSource(url)
             )
+        component.node_key = key
         component.download(salt=salt, namespace=backend.cache_key)
 
         source_dir = component.source_dir
diff --git a/tests/unit_tests/test_arduino_library.py b/tests/unit_tests/test_arduino_library.py
index 59a1f9fa45..ebc03da497 100644
--- a/tests/unit_tests/test_arduino_library.py
+++ b/tests/unit_tests/test_arduino_library.py
@@ -552,3 +552,57 @@ def test_bundled_dependency_platform_rejection_is_debug(
             cache_key="arduino8266",
         )
     assert "Skipping bundled dependency Wire" not in caplog.text
+
+
+@pytest.mark.parametrize("data", [{"build": "src"}, [], "nope"])
+def test_library_info_malformed_manifest_is_named(tmp_path: Path, data: object) -> None:
+    """A malformed manifest names the library, never an AttributeError."""
+    read_path = tmp_path / "lib"
+    read_path.mkdir()
+    with pytest.raises(EsphomeError, match="Library x has a malformed manifest"):
+        component._library_info("x", read_path, data)
+
+
+def test_drop_warning_maps_requests_by_node_key(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A bare request resolving to a canonical name is not falsely reported
+    missing; the genuinely dropped request is the one named."""
+    framework = _make_framework(tmp_path)
+    _add_library("pngle", None)
+    _add_library("gone/missing", "1.0.0")
+    lib_dir = tmp_path / "converted" / "pngle"
+    (lib_dir / "src").mkdir(parents=True)
+    resolved = _converted("bitbank2__pngle", lib_dir, {"build": {}})
+    resolved.node_key = "pngle"
+    with patch.object(component, "convert_libraries", return_value=[resolved]):
+        component.resolve_libraries(
+            framework,
+            pio_platform="espressif8266",
+            board_mcu="esp8266",
+            cache_key="arduino8266",
+        )
+    assert "1 of 2 requested libraries were not resolved" in caplog.text
+    assert "missing" in caplog.text
+    assert "pngle" not in caplog.text.split("missing:")[-1]
+    assert "gone/missing" in caplog.text.split("missing:")[-1]
+
+
+def test_bundled_library_with_declared_dependencies_warns(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A bundled manifest that declares dependencies is visible, not
+    silently skipped (a no-op for the ESP8266 core, not for every core)."""
+    framework = _make_framework(tmp_path)
+    wire = framework / "libraries" / "Wire"
+    (wire / "library.json").write_text(
+        '{"name": "Wire", "dependencies": [{"name": "SPI"}]}'
+    )
+    _add_library("Wire", None)
+    component.resolve_libraries(
+        framework,
+        pio_platform="espressif8266",
+        board_mcu="esp8266",
+        cache_key="arduino8266",
+    )
+    assert "Bundled library Wire declares dependencies" in caplog.text