https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119175
--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
The infinite looping happens in:
#86 0x000000000061032f in write_expression (expr=<requires_expr
0x7fffe9a30180>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3807
#87 0x00000000005ff225 in write_constraint_expression (expr=<requires_expr
0x7fffe9a30180>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:860
#88 0x00000000005ff42b in write_tparms_constraints (constraints=<requires_expr
0x7fffe9a30180>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:894
#89 0x0000000000605aef in write_closure_template_head (tmpl=<template_decl
0x7fffe9bbf110 operator()>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1974
#90 0x0000000000605c5c in write_closure_type_name (type=<record_type
0x7fffe9ba4b28 ._anon_0>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1994
#91 0x0000000000603a9a in write_unqualified_name (decl=<type_decl
0x7fffe9a36e60 ._anon_0>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1592
#92 0x0000000000601ae9 in write_prefix (node=<record_type 0x7fffe9ba4b28
._anon_0>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1363
#93 0x000000000060152f in write_nested_name (decl=<type_decl 0x7fffe9bbe000
._anon_1>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1279
#94 0x0000000000600aa0 in write_name (decl=<type_decl 0x7fffe9bbe000 ._anon_1>,
ignore_local_scope=0)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1171
#95 0x000000000060ba69 in write_class_enum_type (type=<record_type
0x7fffe9ba4c78 ._anon_1>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3103
#96 0x000000000060864a in write_type (type=<record_type 0x7fffe9ba4c78
._anon_1>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:2516
#97 0x000000000061029f in write_expression (expr=<lambda_expr 0x7fffe9bbc050>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3803
#98 0x000000000060bb56 in write_requirement (req=<simple_req 0x7fffe9bb92e0>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3120
#99 0x000000000060c165 in write_requires_expr (expr=<requires_expr
0x7fffe9a30180>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3172
#100 0x000000000061032f in write_expression (expr=<requires_expr
0x7fffe9a30180>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3807
#101 0x00000000005ff225 in write_constraint_expression (expr=<requires_expr
0x7fffe9a30180>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:860
#102 0x00000000005ff42b in write_tparms_constraints (constraints=<requires_expr
0x7fffe9a30180>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:894
#103 0x0000000000605aef in write_closure_template_head (tmpl=<template_decl
0x7fffe9bbf110 operator()>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1974
#104 0x0000000000605c5c in write_closure_type_name (type=<record_type
0x7fffe9ba4b28 ._anon_0>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1994
#105 0x0000000000603a9a in write_unqualified_name (decl=<type_decl
0x7fffe9a36e60 ._anon_0>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1592
#106 0x0000000000601ae9 in write_prefix (node=<record_type 0x7fffe9ba4b28
._anon_0>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1363
#107 0x000000000060152f in write_nested_name (decl=<type_decl 0x7fffe9bbe000
._anon_1>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1279
#108 0x0000000000600aa0 in write_name (decl=<type_decl 0x7fffe9bbe000
._anon_1>, ignore_local_scope=0)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:1171
#109 0x000000000060ba69 in write_class_enum_type (type=<record_type
0x7fffe9ba4c78 ._anon_1>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3103
#110 0x000000000060864a in write_type (type=<record_type 0x7fffe9ba4c78
._anon_1>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:2516
#111 0x000000000061029f in write_expression (expr=<lambda_expr 0x7fffe9bbc050>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3803
#112 0x000000000060bb56 in write_requirement (req=<simple_req 0x7fffe9bb92e0>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3120
#113 0x000000000060c165 in write_requires_expr (expr=<requires_expr
0x7fffe9a30180>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3172
#114 0x000000000061032f in write_expression (expr=<requires_expr
0x7fffe9a30180>)
at /home/mpolacek/src/gcc/gcc/cp/mangle.cc:3807
