[Gimp-user] Precompiled GIMP on macOS does not recognize plugins

[raxod502 <forums gimpusers com>]

I am attempting to install the Resynthesizer plugin for GIMP on macOS 10.11.6.

I installed GIMP 2.8.22 using Homebrew Cask
  https://github.com/caskroom/homebrew-cask/blob/master/Casks/gimp.rb
and downloaded the Resynthesizer plugin version 1.0 from
  http://registry.gimp.org/node/27986

According to Preferences > Folders, the following directories are used for
plug-ins
  /Users/raxod502/Library/Application Support/GIMP/2.8/plug-ins
  /Applications/GIMP.app/Contents/Resources/lib/gimp/2.0/plug-ins

The contents of the former are
  Permissions Size User     Date Modified Name
  .rw-r--r--@ 6.6k raxod502 13 Apr  2011  plugin-heal-selection.py
  .rw-r--r--@ 3.2k raxod502 13 Apr  2011  plugin-heal-transparency.py
  .rw-r--r--@  17k raxod502 13 Apr  2011  plugin-map-style.py
  .rw-r--r--@ 7.7k raxod502 13 Apr  2011  plugin-render-texture.py
  .rw-r--r--@ 3.3k raxod502 13 Apr  2011  plugin-resynth-enlarge.py
  .rw-r--r--@ 3.6k raxod502 15 Apr  2011  plugin-resynth-fill-pattern.py
  .rw-r--r--@ 3.3k raxod502 13 Apr  2011  plugin-resynth-sharpen.py
  .rw-r--r--@ 6.0k raxod502 13 Apr  2011  plugin-uncrop.py
  .rwxr-xr-x@  62k raxod502 15 Apr  2011  resynthesizer
  .rwxr-xr-x@  53k raxod502 15 Apr  2011  resynthesizer-gui

On restarting GIMP, I believe there should be a menu entry Filter > Enhance >
Heal selection (among others), but there is no such item. Furthermore, I get no
results from Help > Plug-In Browser when searching for either "heal" or
"resynthesizer".

Have I misunderstood how to install plugins? Is there some kind of compilation
step? Any way I can debug the situation?

-- 
raxod502 (via www.gimpusers.com/forums)