<flag name="gnat_2016">Compile with dev-lang/gnat-gpl-2016</flag>
<flag name="gnat_2017">Compile with dev-lang/gnat-gpl-2017</flag>
<flag name="gnat_2018">Compile with dev-lang/gnat-gpl-2018</flag>
+ <flag name="gnat_2019">Compile with dev-lang/gnat-gpl-2019</flag>
<flag name="shared">Build shared library</flag>
<flag name="static-pic">Build shared library</flag>
</use>