`fptr01` fails in the `sanity` way
The fptr01
test fails when sanity-checking is enabled due to an assertion failure:
h33
g33
f33
f_env 3 35
f_env 2 35
f_env 1 35
fptr01: internal error: ASSERTION FAILED: file rts/sm/Sanity.c, line 333
(GHC version 9.1.20210103 for x86_64_unknown_linux)
Please report this as a GHC bug: https://www.haskell.org/ghc/reportabug
Aborted
The cause is quite straightforward: the weak pointer list check in checkGenWeakPtrList
(added by b1d2c1f3) failed to account for the fact that weak pointers may have DEAD_WEAK
closure type.