macOS: Library not loaded: /usr/local/opt/readline/lib/libreadline.7.dylib

If you get:

[jerome@jeroboam] > psql mydb
dyld: Library not loaded: /usr/local/opt/readline/lib/libreadline.7.dylib
  Referenced from: /usr/local/bin/psql
  Reason: image not found
Abort trap: 6

Fix it with:

[jerome@jeroboam] > ln -s /usr/local/opt/readline/lib/libreadline.8.0.dylib /usr/local/opt/readline/lib/libreadline.7.dylib