/usr/lib/hugs/ is in libhugs-mtl-bundled 98.200609.21-5.3ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/hugs/packages/
/usr/lib/hugs/packages/mtl/
/usr/lib/hugs/packages/mtl/Control/
/usr/lib/hugs/packages/mtl/Control/Monad/
/usr/lib/hugs/packages/mtl/Control/Monad/Cont.hs
/usr/lib/hugs/packages/mtl/Control/Monad/Error.hs
/usr/lib/hugs/packages/mtl/Control/Monad/Identity.hs
/usr/lib/hugs/packages/mtl/Control/Monad/List.hs
/usr/lib/hugs/packages/mtl/Control/Monad/RWS.hs
/usr/lib/hugs/packages/mtl/Control/Monad/Reader.hs
/usr/lib/hugs/packages/mtl/Control/Monad/State.hs
/usr/lib/hugs/packages/mtl/Control/Monad/Trans.hs
/usr/lib/hugs/packages/mtl/Control/Monad/Writer.hs
/usr/lib/hugs/packages/mtl/Paths_mtl.hs