libghc-threads-doc 0.5.1.6-4build2 (amd64 binary) in ubuntu hirsute

 This package provides functions to fork threads and wait for their result,
 whether it's an exception or a normal value.
 .
 Besides waiting for the termination of a single thread this package also
 provides functions to wait for a group of threads to terminate.
 .
 This package provides the documentation for a library for the Haskell
 programming language.
 See http://www.haskell.org/ for more information on Haskell.