There is a new pull request by hills against master on the void-packages repository

https://github.com/hills/void-packages ortp
https://github.com/void-linux/void-packages/pull/16331

ortp-devel: users of this library will depend on bctoolbox for builds
It has a header file dependency:

  /usr/include/ortp/rtpsession.h:34:10: fatal error: bctoolbox/list.h: No such file or directory

I looked at SDL_ttf and followed the pattern for how it deals with
the same situation.

A patch file from https://github.com/void-linux/void-packages/pull/16331.patch is attached