The build container was pinned to espressif/idf:release-v5.3, but the firmware is actually developed against v6.0.2 (this machine's $IDF_PATH). That gap caused real compile failures in CI -- esp_sleep_enable_gpio_wakeup_on_hp_periph_powerdown and ESP_NETIF_CAPTIVEPORTAL_URI are both newer than v5.3 has, plus a transitive stdbool.h include that changed between versions -- none of it a real bug in the source.