Dyld

$ virsh
dyld: Library not loaded: /usr/local/opt/libffi/lib/libffi.7.dylib
  Referenced from: /usr/local/opt/glib/lib/libgobject-2.0.0.dylib
  Reason: image not found
$ brew install glib
...
$ virsh
Welcome to virsh, the virtualization interactive terminal.

Type:  'help' for help with commands
       'quit' to quit

virsh #

$ virt-manager
Traceback (most recent call last):
  File "/usr/local/Cellar/virt-manager/2.2.1_3/libexec/share/virt-manager/virt-manager", line 15, in <module>
    import gi
  File "/usr/local/opt/pygobject3/lib/python3.9/site-packages/gi/__init__.py", line 40, in <module>
    from . import _gi
ImportError: dlopen(/usr/local/opt/pygobject3/lib/python3.9/site-packages/gi/_gi.cpython-39-darwin.so, 2): Library not loaded: /usr/local/opt/libffi/lib/libffi.7.dylib
  Referenced from: /usr/local/opt/pygobject3/lib/python3.9/site-packages/gi/_gi.cpython-39-darwin.so
  Reason: image not found
$ brew reinstall pygobject3