esp-idf/tools/kconfig_new/config.env.in

{
    "COMPONENT_KCONFIGS": "${kconfigs}",
    "COMPONENT_KCONFIGS_PROJBUILD": "${kconfig_projbuilds}",
    "COMPONENT_SDKCONFIG_RENAMES": "${sdkconfig_renames}",
    "IDF_CMAKE": "y",
    "IDF_TARGET": "${idf_target}",
    "IDF_PATH": "${idf_path}",
    "COMPONENT_KCONFIGS_SOURCE_FILE": "${kconfigs_path}",
    "COMPONENT_KCONFIGS_PROJBUILD_SOURCE_FILE": "${kconfigs_projbuild_path}"
}