Urrgh. I have this panic in a clean validate (sh validate –fast) on my branch wip/T15809.

ghc-stage1: panic! (the 'impossible' happened)

  (GHC version 8.7.20181119 for x86_64-unknown-linux):

       split_marker_entry

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

libraries/ghc-prim/ghc.mk:4: recipe for target 'libraries/ghc-prim/dist-install/build/GHC/Types.o' failed

Yes, it’s a branch not identical to HEAD, but I have done nothing concerning split_markers.

Sigh. What should I do?

Simon