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

-- example from #7231, modified: the example in the ticket did not
-- trigger the bug, because a module containing only '"' will fail
-- in the downsweep, which is before we unload modules.  Hence this
-- repro case uses a module that contains an unbound identifier and
-- fails in the renamer.

:shell cp Bar1.hs Bar.hs

:load FooBar.hs
:shell sleep 1
:shell cp Bar2.hs Bar.hs

:reload
foo