[MacPorts] #60249: lilypond @2.20.0 doesn't have mactex variant

[MacPorts]

#60249: lilypond @2.20.0 doesn't have mactex variant
--------------------------+----------------------
  Reporter:  rpspringuel  |      Owner:  nerdling
      Type:  enhancement  |     Status:  assigned
  Priority:  Normal       |  Milestone:
 Component:  ports        |    Version:  2.6.2
Resolution:               |   Keywords:
      Port:  lilypond     |
--------------------------+----------------------

Comment (by lemzwerg):

 A first step: https://github.com/macports/macports-ports/pull/6728

 Next step is to add the `mactex` variant to the 'lilypond' Portfile (in a
 separate pull request).

 I guess the differences will be then small enough to make subports.
 However, I have no idea how to do that, so any guidance will be much
 appreciated.

-- 
Ticket URL: <https://trac.macports.org/ticket/60249#comment:2>
MacPorts <https://www.macports.org/>
Ports system for macOS