oh-my-zsh now writes `LESS` in `lib/misc.zsh`, and this is invoked after zshenv.
@@ -0,0 +1 @@
+export LESS='-eirMX'
@@ -8,7 +8,6 @@
#
## don't close less when I am done reading
-export LESS='-eirMX'
export EDITOR='vim'
## paths