Package: libfltk1.4-dev Version: 1.4.2-6 Severity: important Dear Maintainer,
fltk1.4 is built with Cairo support, so it ends up relying on cairo.h etc. during builds: FL/Fl.H includes FL_Cairo.H, which includes cairo.h. This means that packages relying on libfltk1.4-dev need libcairo2-dev, even if they don’t use Cairo features themselves. That dependency should be carried by libfltk1.4-dev. Regards, Stephen
