Actually there is no build for GIMP 2.10!
Neither on GimponOSX nor on Gimp.org exists a build for MacOS!
ADDITIONALLY the gtk plugin has been abandoned due to several improvements in GUI scripting since version 2.3.0
It is unlikely that this type of linking the plugin against a Gimp build will be possible in future! There is actually only the Partha Gimp build or the more cumbersome way via a package manager as described in GIMP download page for OSX. Personally I use successfully MacPort for gmic (and GIMP) as well as the git repositories gmic, CImg, gmic-qt and zart to get the most recent (beta) version.
The dmg file consists of two builds of gmic_gimp plugins. The formerly added gmic cli exists now as port gmic in MacPorts and can be installed by "sudo port install gmic".
Only the git build has the cli (/Volumes/Macgmic/cli/gmic) linked against MacPorts. Users of this cli need installed MacPorts at standard location /opt/local !
Some news: There is actually NO qt plugin, since the used Gimp bundles don't have the necessary libraries! Have a look into the Partha Gimp build!
The gimp gmic plugins (gmic_gimp_gtk for Gimp from
rspw. gmic_gimp_ngtk) for Gimp from GIMP
are linked against libraries in the respective Gimp.app bundle using the mechanism adoped there in.
Gimp from GIMPonOSX is creating upon start a symbolic link under /tmp/skl/Gimp! Gimp from GIMP.org uses a different mechanism not relying on the method stated above.
Typical Gimp users have only to copy the plugin gmic_gimp_gtk resp. gmic_gimp_ngtk to the user plugins folder set in the Gimp preferences! Unluckily only one of the two plugins should reside in the plugins folder, Gimp builds are using the same set of preferences!
Gimp users take care using the referenced Gimp build, actually 2.8.18 for the stable build from GIMPonOSX (see Downloads) rspw. 2.8.22, from GIMP for the git builds!
For information or problems, send mail to karo<zero><three>de at gmail dot com.