The above solution unfortunately doesn't work for those of us who use fzf (or other fuzzy runners), since that RUN_SCARY_THINGY=yes var will be part of the matched line which you will run inadvertently in your coffee-deprived mind. I rarely make mistakes while consciously typing out commands, but running commands with wrong arguments because I didn't pay enough attention on the matched line does happen semi-regularly. Doesn't help that since doing stuff with fzf is much faster than typing out full commands, that your brain sometimes just doesn't have enough time to ask -- wait, should I be running this right now?