`internal error: update_fwd_large: unknown/strange object 38`

Summary

whist running our program the following error is encountered and the process stops (have replaced name with my-program)

Oct 23 12:30:48 ip-10-0-11-156 sh[10238]: my-program: internal error: update_fwd_large: unknown/strange object  38
Oct 23 12:30:48 ip-10-0-11-156 sh[10238]:     (GHC version 8.6.5 for x86_64_unknown_linux)
Oct 23 12:30:48 ip-10-0-11-156 sh[10238]:     Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug    

Steps to reproduce

Seems to happen during a GC, sometimes the program had called performMajorGC, sometimes memory usage had seemingly triggered one. Only seems to happen when the heap is large (24GB in this example, on a 32GB machine)

we are using -c compacting GC

Expected behavior

What do you expect the reproducer described above to do?

Not crash

Environment

• OS: Ubuntu 18.04 server running on m4.2xlarge in ec2
• Stackage LTS 13.25
• GHC version used: 8.6.5