what is gio-fam?

[Mikhail Teterin]

I'm trying to build graphics/vips, which works. Then I try to install
it, and that suddenly requires devel/gio-fam-backend.

Building that fails:

...
cc -shared  .libs/libgiofam_la-fam-helper.o .libs/libgiofam_la-fam-module.o .libs/libgiofam_la-gfamdirectorymonitor.o .libs/libgiofam_la-gfamfilemonitor.o  -Wl,--rpath -Wl,/opt/lib -Wl,--rpath -Wl,/opt/lib -L/opt/lib /opt/lib/libintl.so -lgio-2.0 /opt/lib/libgobject-2.0.so /opt/lib/libglib-2.0.so /opt/lib/libfam.so  -march=opteron -Wl,-soname -Wl,libgiofam.so -Wl,-retain-symbols-file -Wl,.libs/libgiofam.exp -o .libs/libgiofam.so
/usr/bin/ld: cannot find -lgio-2.0
gmake: *** [libgiofam.la] Помилка 1

What's happening? Thanks!

 -mi