Re: backend hangs at immediate shutdown

As I promised yesterday, I'll show you the precise call stack:

#0 0x0000003fa0cf542e in __lll_lock_wait_private () from /lib64/libc.so.6
#1 0x0000003fa0c7bed5 in _L_lock_9323 () from /lib64/libc.so.6
#2 0x0000003fa0c797c6 in malloc () from /lib64/libc.so.6
#3 0x0000003fa0c2fd99 in _nl_make_l10nflist () from /lib64/libc.so.6
#4 0x0000003fa0c2e0a5 in _nl_find_domain () from /lib64/libc.so.6
#5 0x0000003fa0c2d990 in __dcigettext () from /lib64/libc.so.6
#6 0x00000000006f2a71 in errhint ()
#7 0x0000000000634064 in quickdie ()
#8 <signal handler called>
#9 0x0000003fa0c77813 in _int_free () from /lib64/libc.so.6
#10 0x000000000070e329 in AllocSetDelete ()
#11 0x000000000070e8cb in MemoryContextDelete ()
#12 0x0000000000571723 in FreeExprContext ()
#13 0x0000000000571781 in FreeExecutorState ()
#14 0x00000000005dc883 in evaluate_expr ()
#15 0x00000000005ddca0 in simplify_function ()
#16 0x00000000005de69f in eval_const_expressions_mutator ()
#17 0x0000000000599143 in expression_tree_mutator ()
#18 0x00000000005de452 in eval_const_expressions_mutator ()
#19 0x0000000000599143 in expression_tree_mutator ()
#20 0x00000000005de452 in eval_const_expressions_mutator ()
#21 0x00000000005dfa2f in eval_const_expressions ()
#22 0x00000000005cf16d in preprocess_expression ()
#23 0x00000000005d2201 in subquery_planner ()
#24 0x00000000005d23cf in standard_planner ()
#25 0x000000000063426a in pg_plan_query ()
#26 0x0000000000634354 in pg_plan_queries ()
#27 0x0000000000635310 in exec_simple_query ()
#28 0x0000000000636333 in PostgresMain ()
#29 0x00000000005f64e9 in PostmasterMain ()
#30 0x0000000000596e20 in main ()