harfbuzz upgrade to 1.7.6 breaks xfce4
After the recent upgrade from harfbuzz 1.6.3 to harfbuzz 1.7.6., xfce4 fails to start (e.g. startxfce4) and returns the error:
Error relocating /usr/lib/libharfbuzz.so.0: FT_Done_MM_Var: symbol not found
As a standard user, the above control returns to the terminal where the above error is seen. As root, the system freezes and must be reset.
(from redmine: issue id 8661, created on 2018-03-16)