Error: Failed to archivefetch pango: cairo is required, but not active

[ryandesign (Ryan Carsten Schmidt)]

There is something wrong with either mpbb or the active_variants portgroup.

See attached log from Travis, which is trying to install dependencies of a port. It successfully installs and then deactivates 135 dependencies, then tries to build dependency 136, which is pango. The log ends with:

----> Installing dependency (136 of 235) 'pango' with variants '+quartz+x11' (requesting '')

--->  Fetching archive for pango
DEBUG: Executing proc-pre-org.macports.archivefetch-archivefetch-0
DEBUG: Active variants check for archivefetch-type install considers depends_lib depends_run: glib2 cairo fribidi harfbuzz gobject-introspection Xft2
DEBUG: Checking cairo for active variants for depspec 'path:lib/pkgconfig/cairo.pc:cairo'
Error: Failed to archivefetch pango: cairo is required, but not active.