{pkgs, piston, ...}: let pkg = pkgs.crystal; in piston.mkRuntime { language = "crystal"; version = pkg.version; aliases = [ "cr" ]; compile = '' ${pkg}/bin/crystal build "$@" -o out --no-color chmod +x out ''; run = '' shift ./out "$@" ''; tests = [ (piston.mkTest { files = { "test.cr" = '' puts("OK") ''; }; }) ]; }