Hi
I have a recipe for a library. It install .so files correctly but headers not installed. It can install files any where except /usr/inclue/ directory. 

SUMMARY = "An open source library for DNP3"

HOMEPAGE = "http://dnp3.github.io/"

SECTION = "libs"

DEPENDS = ""

LICENSE = "Apache-2.0"

LIC_FILES_CHKSUM = "file://LICENSE;md5=3b83ef96387f14655fc854ddc3c6bd57"

SRCREV = "639edaf1a5d2d74bc04efdd9ddf165bc14a06390"

SRC_URI = "git://github.com/dnp3/opendnp3.git;branch=release" 

S = "${WORKDIR}/git"

EXTRA_OECMAKE += "-DNP3_TLS=ON"

do_install_append(){

    install -d ${D}${includedir}

    cp -r ${S}/cpp/lib/include/opendnp3 ${D}${includedir}

}

FILES_${PN} += "${includedir}"

inherit cmake

Where is my mistake? 
Thanks.