Fix stack's haddock build failure (fpco/stackage#802)
Fix stack's haddock build failure (fpco/stackage#802)

martin-kolinek/stack,cabrera/stack,fizruk/stack,bollu/stack,AndreasPK/stack,Heather/stack,MichielDerhaeg/stack,fizruk/stack,deech/stack,bollu/stack,robstewart57/stack,adinapoli/stack,akhileshs/stack,sjakobi/stack,cabrera/stack,vigoo/stack,rubik/stack,harendra-kumar/stack,tedkornish/stack,athanclark/stack,deech/stack,sinelaw/stack,AndreasPK/stack,keent/stack,rvion/stack,anton-dessiatov/stack,mathhun/stack,luigy/stack,juhp/stack,mrkkrp/stack,lukexi/stack,Blaisorblade/stack,athanclark/stack,MaxGabriel/stack,sjakobi/stack,Heather/stack,bixuanzju/stack,phadej/stack,rrnewton/stack,luigy/stack,AndrewRademacher/stack,tedkornish/stack,juhp/stack,wolftune/stack,rvion/stack,wolftune/stack,supermario/stack,mrkkrp/stack,mathhun/stack,sinelaw/stack,Andrew-the-Ubergeek/stack,achernyak/stack,Blaisorblade/stack,keent/stack,rrnewton/stack,narrative/stack,MichielDerhaeg/stack,akhileshs/stack,achernyak/stack,bixuanzju/stack,robstewart57/stack,AndrewRademacher/stack,narrative/stack,meiersi-11ce/stack,adinapoli/stack,Fuuzetsu/stack,kairuku/stack,anton-dessiatov/stack,MaxGabriel/stack,vigoo/stack,phadej/stack,harendra-kumar/stack,rubik/stack,Andrew-the-Ubergeek/stack,martin-kolinek/stack,Fuuzetsu/stack,lukexi/stack,kairuku/stack,supermario/stack,meiersi-11ce/stack