Gettext development files?

While installing Cairo on Julia 0.6 gettext is required.
Normally this requires just that one find the relevant gettext-devel package and the process continues.
But for Leap 42.3 there is just a gettext-runtime available; the installation process is able to continue (for me) by obtaining a development package from a different source.
So I’m just wondering what is special about gettext that no devel file is available? Perhaps it just has an odd name?