https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91793
--- Comment #2 from Cyp <cyp561 at gmail dot com> --- Compiler output from reduced testcase: ------------------- 91793.cpp: In instantiation of ‘<lambda(auto:1 ...)> [with auto:1 = {}]’: 91793.cpp:6:4: required from here 91793.cpp:4:25: internal compiler error: Segmentation fault using b = decltype(a); ^ 0xb61e5f crash_signal /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/toplev.c:325 0x7f1b8e9f202f ??? /var/tmp/portage/sys-libs/glibc-2.29-r2/work/glibc-2.29/signal/../sysdeps/unix/sysv/linux/x86_64/sigaction.c:0 0x70ea21 invalid_nonstatic_memfn_p(unsigned int, tree_node*, int) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/typeck.c:1887 0x6f546a finish_decltype_type(tree_node*, bool, int) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/semantics.c:8769 0x6c5661 tsubst(tree_node*, tree_node*, int, tree_node*) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:14982 0x6d6734 tsubst_decl /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:13704 0x6c5d5f tsubst(tree_node*, tree_node*, int, tree_node*) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:14217 0x6c2b31 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:16707 0x6c17ae tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:16930 0x6c17ae tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:16930 0x6d7578 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:16615 0x6d7578 tsubst_lambda_expr(tree_node*, tree_node*, int, tree_node*) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:17685 0x6cee41 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:18971 0x6c22d4 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:17446 0x6c2098 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:16644 0x6c18e6 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:16630 0x6c17ae tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:16930 0x6c17ae tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:16930 0x6c03a3 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:16615 0x6c03a3 instantiate_decl(tree_node*, bool, bool) /var/tmp/portage/sys-devel/gcc-8.3.0-r1/work/gcc-8.3.0/gcc/cp/pt.c:24066 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://bugs.gentoo.org/> for instructions.