The part with changing the Boost Makefile is bullshit.
Singnals2 is inside Signals.
I tried doing the right configuration already in the configure part. but didn't succeed.

make clean make cd ../wpantund export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/home/fabian/test/source//staging_dir/target-mipsel_24kc_musl-1.1.16/usr/lib/pkgconfig ./configure --host=mipsel-openwrt-linux ac_cv_search_readline=/home/fabian/test/source//staging_dir/target-mipsel_24kc_musl-1.1.16/usr/lib/libreadline.so CC=/home/fabian/test/source//staging_dir/toolchain-mipsel_24kc_gcc-5.4.0_musl-1.1.16/bin/mipsel-openwrt-linux-gcc CXX=/home/fabian/test/source//staging_dir/toolchain-mipsel_24kc_gcc-5.4.0_musl-1.1.16/bin/mipsel-openwrt-linux-g++ CCLD=/home/fabian/test/source//staging_dir/toolchain-mipsel_24kc_gcc-5.4.0_musl-1.1.16/bin/mipsel-openwrt-linux-ld CXXLD=/home/fabian/test/source//staging_dir/toolchain-mipsel_24kc_gcc-5.4.0_musl-1.1.16/bin/mipsel-openwrt-linux-ld CFLAGS="$(pkg-config dbus-1 --cflags)"

this time doesn't finde the dbus lib
wich is in /home/fabian/test/source//staging_dir/target-mipsel_24kc_musl-1.1.16/usr/lib/dbus-1.0/include/

In file included from wpanctl.c:47:0: /usr/include/dbus-1.0/dbus/dbus.h:29:33: fatal error: dbus/dbus-arch-deps.h: No such file or directory compilation terminated.

The package config path is defined to /home/fabian/test/source//staging_dir/target-mipsel_24kc_musl-1.1.16/usr/lib/pkgconfig
there is a dbus-1.pc file

pkg-config --cflags dbus-1 -I/usr/include/dbus-1.0 -I/usr/lib/dbus-1.0/include

it gives me the dir to the dbus lib where the dbus-arch-deps.h file is
why can't dbus.h include find this file?
any suggestions?