:l shell.hs
:def shell (\s -> do shell s; return "")

:set -v1
System.IO.writeFile "T1914A.hs" "module T1914A where { import T1914B; }"
System.IO.writeFile "T1914B.hs" "module T1914B where { type T = Int; }"
:load T1914A
System.IO.writeFile "T1914A.hs" "module T1914A where { import T1914B; oops }"
:reload
-- T1914B should still be loaded
:module *T1914B
System.IO.writeFile "T1914A.hs" "module T1914A where { import T1914B; }"
:shell echo >> T1914A.hs
:reload
-- should not have to reload T1914B