Your bug report

#31726: haskell-mode fails to build with (at least) Emacs 26.1

which was filed against the guix package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to 31726@debbugs.gnu.org.

-- 
31726: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=31726
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