We assume that you are using a fresh macOS installation.
Install Homebrew package manager
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"brew install idris cabal-install git ghc python wgetInstall MacTeX via Homebrew
brew cask install mactexcabal update
cabal install pandoc pandoc-types
export PATH=$HOME/.cabal/bin:$PATHYou might want to add cabal to your PATH permanently.
pip install --user PygmentsDownload the Iosevka font and put the ttf-files into /Library/Fonts directory.
Reboot to let macOS find the font.