https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93140
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Seems mutual infinite recursion:
...
#101 0x0000000000b83f51 in tsubst_decl (t=<parm_decl 0x7fffea81d180 x>,
args=<tree_vec 0x7fffea94e7a0>, complain=0) at ../../gcc/cp/pt.c:14083
#102 0x0000000000b87bc3 in tsubst (t=<parm_decl 0x7fffea81d180 x>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<parm_decl 0x7fffea81d180 x>) at ../../gcc/cp/pt.c:14930
#103 0x0000000000b83d4b in tsubst_decl (t=<parm_decl 0x7fffea81d100 r>,
args=<tree_vec 0x7fffea94e7a0>, complain=0) at ../../gcc/cp/pt.c:14048
#104 0x0000000000b7a102 in tsubst_pack_expansion (t=<expr_pack_expansion
0x7fffea9603f0>, args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<parm_decl 0x7fffea81d180 x>) at ../../gcc/cp/pt.c:12749
#105 0x0000000000ba05e8 in tsubst_copy_and_build (t=<call_expr 0x7fffea800118>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<parm_decl 0x7fffea81d180 x>, function_p=false,
integral_constant_expression_p=false) at ../../gcc/cp/pt.c:19438
#106 0x0000000000b8b312 in tsubst (t=<decltype_type 0x7fffea966000>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<parm_decl 0x7fffea81d180 x>) at ../../gcc/cp/pt.c:15688
#107 0x0000000000b83f51 in tsubst_decl (t=<parm_decl 0x7fffea81d180 x>,
args=<tree_vec 0x7fffea94e7a0>, complain=0) at ../../gcc/cp/pt.c:14083
#108 0x0000000000b87bc3 in tsubst (t=<parm_decl 0x7fffea81d180 x>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<parm_decl 0x7fffea81d180 x>) at ../../gcc/cp/pt.c:14930
#109 0x0000000000b83d4b in tsubst_decl (t=<parm_decl 0x7fffea81d100 r>,
args=<tree_vec 0x7fffea94e7a0>, complain=0) at ../../gcc/cp/pt.c:14048
#110 0x0000000000b7a102 in tsubst_pack_expansion (t=<expr_pack_expansion
0x7fffea9603f0>, args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<parm_decl 0x7fffea81d180 x>) at ../../gcc/cp/pt.c:12749
#111 0x0000000000ba05e8 in tsubst_copy_and_build (t=<call_expr 0x7fffea800118>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<parm_decl 0x7fffea81d180 x>, function_p=false,
integral_constant_expression_p=false) at ../../gcc/cp/pt.c:19438
#112 0x0000000000b8b312 in tsubst (t=<decltype_type 0x7fffea966000>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<parm_decl 0x7fffea81d180 x>) at ../../gcc/cp/pt.c:15688
#113 0x0000000000b83f51 in tsubst_decl (t=<parm_decl 0x7fffea81d180 x>,
args=<tree_vec 0x7fffea94e7a0>, complain=0) at ../../gcc/cp/pt.c:14083
#114 0x0000000000b87bc3 in tsubst (t=<parm_decl 0x7fffea81d180 x>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<parm_decl 0x7fffea81d180 x>) at ../../gcc/cp/pt.c:14930
#115 0x0000000000b83d4b in tsubst_decl (t=<parm_decl 0x7fffea81d100 r>,
args=<tree_vec 0x7fffea94e7a0>, complain=0) at ../../gcc/cp/pt.c:14048
#116 0x0000000000b7a102 in tsubst_pack_expansion (t=<expr_pack_expansion
0x7fffea9603f0>, args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<function_decl 0x7fffea951f00 foo>) at ../../gcc/cp/pt.c:12749
#117 0x0000000000ba05e8 in tsubst_copy_and_build (t=<call_expr 0x7fffea800118>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<function_decl 0x7fffea951f00 foo>, function_p=false,
integral_constant_expression_p=false) at ../../gcc/cp/pt.c:19438
#118 0x0000000000b8b312 in tsubst (t=<decltype_type 0x7fffea966000>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<function_decl 0x7fffea951f00 foo>) at ../../gcc/cp/pt.c:15688
#119 0x0000000000b86bdb in tsubst_arg_types (arg_types=<tree_list
0x7fffea965190>, args=<tree_vec 0x7fffea94e7a0>, end=<tree 0x0>, complain=0,
in_decl=<function_decl 0x7fffea951f00 foo>) at ../../gcc/cp/pt.c:14600
#120 0x0000000000b86a43 in tsubst_arg_types (arg_types=<tree_list
0x7fffea965168>, args=<tree_vec 0x7fffea94e7a0>, end=<tree 0x0>, complain=0,
in_decl=<function_decl 0x7fffea951f00 foo>) at ../../gcc/cp/pt.c:14569
#121 0x0000000000b871fa in tsubst_function_type (t=<function_type
0x7fffea9660a8>, args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<function_decl 0x7fffea951f00 foo>) at ../../gcc/cp/pt.c:14742
#122 0x0000000000b8a4e2 in tsubst (t=<function_type 0x7fffea9660a8>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<function_decl 0x7fffea951f00 foo>) at ../../gcc/cp/pt.c:15495
#123 0x0000000000b7eb2d in tsubst_function_decl (t=<function_decl
0x7fffea951f00 foo>, args=<tree_vec 0x7fffea94e7a0>, complain=0,
lambda_fntype=<tree 0x0>) at ../../gcc/cp/pt.c:13575
#124 0x0000000000b83afd in tsubst_decl (t=<function_decl 0x7fffea951f00 foo>,
args=<tree_vec 0x7fffea94e7a0>, complain=0)
at ../../gcc/cp/pt.c:14013
#125 0x0000000000b87bc3 in tsubst (t=<function_decl 0x7fffea951f00 foo>,
args=<tree_vec 0x7fffea94e7a0>, complain=0,
in_decl=<template_decl 0x7fffea81d200 foo>) at ../../gcc/cp/pt.c:14930
#126 0x0000000000ba61d7 in instantiate_template_1 (tmpl=<template_decl
0x7fffea81d200 foo>, orig_args=<tree_vec 0x7fffea94e7a0>, complain=0)
at ../../gcc/cp/pt.c:20468
#127 0x0000000000ba68aa in instantiate_template (tmpl=<template_decl
0x7fffea81d200 foo>, orig_args=<tree_vec 0x7fffea94e7a0>, complain=0)
at ../../gcc/cp/pt.c:20525
#128 0x0000000000ba7f71 in fn_type_unification (fn=<template_decl
0x7fffea81d200 foo>, explicit_targs=<tree 0x0>,
targs=<tree_vec 0x7fffea94e7a0>, args=0x7fffffffbc00, nargs=1,
return_type=<tree 0x0>, strict=DEDUCE_CALL, flags=1, convs=0x3595320,
explain_p=false, decltype_p=false) at ../../gcc/cp/pt.c:20969
#129 0x00000000008e9a4d in add_template_candidate_real
(candidates=0x7fffffffbf30, tmpl=<template_decl 0x7fffea81d200 foo>,
ctype=<tree 0x0>,
explicit_targs=<tree 0x0>, first_arg=<tree 0x0>, arglist=0x7fffea965078,
return_type=<tree 0x0>, access_path=<tree 0x0>,
conversion_path=<tree 0x0>, flags=1, obj=<tree 0x0>, strict=DEDUCE_CALL,
complain=3) at ../../gcc/cp/call.c:3394
#130 0x00000000008e9fc0 in add_template_candidate (candidates=0x7fffffffbf30,
tmpl=<template_decl 0x7fffea81d200 foo>, ctype=<tree 0x0>,
explicit_targs=<tree 0x0>, first_arg=<tree 0x0>, arglist=0x7fffea965078,
return_type=<tree 0x0>, access_path=<tree 0x0>,
conversion_path=<tree 0x0>, flags=1, strict=DEDUCE_CALL, complain=3) at
../../gcc/cp/call.c:3479
#131 0x00000000008f27a1 in add_candidates (fns=<overload 0x7fffea94e720>,
first_arg=<tree 0x0>, args=0x7fffea965078, return_type=<tree 0x0>,
explicit_targs=<tree 0x0>, template_only=false, conversion_path=<tree 0x0>,
access_path=<tree 0x0>, flags=1, candidates=0x7fffffffbf30,
complain=3) at ../../gcc/cp/call.c:5805
#132 0x00000000008ed261 in perform_overload_resolution (fn=<overload
0x7fffea94e720>, args=0x7fffea965078, candidates=0x7fffffffbf30,
any_viable_p=0x7fffffffbf2f, complain=3) at ../../gcc/cp/call.c:4481
#133 0x00000000008ed4d8 in build_new_function_call (fn=<overload
0x7fffea94e720>, args=0x7fffffffc0d0 = {...}, complain=3)
at ../../gcc/cp/call.c:4555
#134 0x0000000000bf02aa in finish_call_expr (fn=<overload 0x7fffea94e720>,
args=0x7fffffffc0d0 = {...}, disallow_virtual=false, koenig_p=true,
complain=3) at ../../gcc/cp/semantics.c:2669
...
