This page gives the commands necessary to disable the diacritical popup menu on a keyboard long-press on Mac OSX machines. These popups typically allow you to add accents and umlauts to vowels, but it interferes with Vim.
These commands are generally taken from this Stack Overflow post.
My setup:
defaults delete -g ApplePressAndHoldEnabled \
; defaults write com.microsoft.VSCode ApplePressAndHoldEnabled -bool false \
; defaults write com.apple.Terminal ApplePressAndHoldEnabled -bool false \
; defaults write com.apple.dt.Xcode ApplePressAndHoldEnabled -bool false
To disable this per application, replace $ID with the name of the application:
default write $ID ApplePressAndHoldEnabled -bool false
To disable this globally:
defaults write -g ApplePressAndHoldEnabled -bool false
To see a list of application/organization names on your machine, run:
defaults domains | tr ',' '\n' | sed 's/^[ \t]*//' | sort