ibus 1.4.0 installs a header file called ibusutil.h, but forgets to include it in ibus.h. ibusutil.h has single-include guards, so it can't be used standalone either. It was clearly meant to be included in ibus.h

Thanks for the correction. I will work on this: https://github.com/fujiwarat/ibus/commit/3dd4b374115f0054ee1fb534eae1f5f9aea79651

https://github.com/ibus/ibus/commit/ee966e327cc3b1b4bba40379bc0fbb3d46c38239