>> +    sed -i -e 's/"-b" "\\n" "-l"/"-l" "-b" "\\"\\\\n\\""/' ghc-process.el
 >
 > If I run ghc-modi -b "\n" -l from the command-line, I get a usage
 > message dumped out. If I run it with the options swapped, it works. This
 > was just something I needed to do to get it to work in my environment.
 > It should be harmless for other environments where it worked previously.

It might be worthwhile to report that issue upstream. I've found that the
ghc-mod authors are very responsive to <https://github.com/kazu-yamamoto/ghc-mod>.