It appears to install fine but does give this warning:
checking host system type... x86_64-pc-linux-gnu
checking for a sed that does not truncate output... /bin/sed
Package xorg-macros was not found in the pkg-config search path.
Perhaps you should add the directory containing `xorg-macros.pc'
to the PKG_CONFIG_PATH environment variable
No package 'xorg-macros' found
checking for RGB... yes
It's OK when native build. But fail when cross-compiling.
Fixed in rgb-1.0.6.