pkg/58788: audio/zynaddsubfx doesn't have a JACK backend although built with JACK option

[bsduck%mailo.com@localhost]

>Number:         58788
>Category:       pkg
>Synopsis:       audio/zynaddsubfx doesn't have a JACK backend although built with JACK option
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Oct 29 13:50:00 +0000 2024
>Originator:     bsduck
>Release:        pkgsrc 2024Q3
>Organization:
>Environment:
NetBSD 10.0 (GENERIC) amd64
>Description:
audio/zynaddsubfx has JACK as one of its build options, which should enable the JACK backend of the synthesizer. Unfortunately, it is ineffective. A package built on NetBSD with this option explicitely enabled still doesn't have a JACK backend available:

$ zynaddsubfx -I jack -O jack

[...]

Error: JACK is not a recognized audio backend
       Defaulting to the NULL audio backend
Error: JACK is not a recognized MIDI input source
       Defaulting to the NULL input source

[...]

Only OSS and NULL backends are available for both audio and MIDI. That's unfortunate because OSS MIDI triggers NetBSD bug #56461 and using JACK would be an easy workaround.

Meanwhile, other synthesizers such as audio/amsynth work fine with JACK on NetBSD, and ZynAddSubFX has a working JACK backend on FreeBSD.
>How-To-Repeat:

>Fix: