A user library that ships a core-named header (e.g. WiFiEspAT/src/WiFi.h)
could shadow the arduino-esp32 core during ESP-IDF library resolution.
WiFiEspAT shadowing WiFi.h pulled EspAtDrv.cpp into the build, whose
const char OK[]/STATUS[] collide with ESP-IDF's enum STATUS in
rom/ets_sys.h, breaking every ESP32 sketch that #include <WiFi.h>.
_resolve_library_components now:
- skips a header entirely when the arduino-esp32 core provides it
(computed set from cores/ + libraries/, cached), so a user lib can
never shadow WiFi.h/Wire.h/SPI.h/WebServer.h/...
- skips a resolved user lib whose library.properties architectures=
excludes esp32/*.
Regression: test/backend/unit/test_espidf_core_first.py
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
