[MLton] Question: What does 'toplevel handler not installed' mean?

[Brent Fulgham]

Just for fun I tried bootstrapping Mingwin again,
but got this error (which is at least, no longer the
"Path Exception" error):

/c/fulgham/projects/mlton.mingwin/build/lib/mlton-compile
@MLton --
/c/fulgham/projects/mlton.mingwin/build/lib/world
MLton bug: toplevel handler not installed.
Please send a bug report to MLton@mlton.org.
make[1]: *** [world-no-check] Error 2


Huh?

-Brent