It would be worth reporting this as a bug to the ghc tracker, as requested in the message.
Emilio Pozuelo Monfort <po...@debian.org> writes: > Source: pandoc > Version: 2.2.1-1 > Severity: serious > > pandoc now FTBFS on armhf with a ghc panic: > > [112 of 131] Compiling Text.Pandoc.Readers.HTML ( > src/Text/Pandoc/Readers/HTML.hs, dist-ghc/build/Text/Pandoc/Readers/HTML.p_o ) > ghc: panic! (the 'impossible' happened) > (GHC version 8.2.2 for arm-unknown-linux): > piResultTy > Addr# > String > Call stack: > CallStack (from HasCallStack): > prettyCurrentCallStack, called at > compiler/utils/Outputable.hs:1133:58 in ghc:Outputable > callStackDoc, called at compiler/utils/Outputable.hs:1137:37 in > ghc:Outputable > pprPanic, called at compiler/types/Type.hs:949:35 in ghc:Type > > Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug > > Full logs at https://buildd.debian.org/status/logs.php?pkg=pandoc&arch=armhf > > Emilio