https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108059
LIU Hao <lh_mouse at 126 dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Known to fail| |10.3.0, 11.1.0 Target| |x86_64-linux-gnu Host| |x86_64-linux-gnu --- Comment #1 from LIU Hao <lh_mouse at 126 dot com> --- Reduced testcase, also ICEs with GCC 10.3.0 and 11.1.0, but 9.4.0 is fine: ``` template <int> using a = int; template <int> auto b() { [](auto... c) { [](a<c>...) {}; }; } template <int d> using e = decltype(b<d>); e<1> f; ``` ``` $ g++-10 -std=c++17 test.cc test.cc: In instantiation of ‘auto b() [with int <anonymous> = 1]’: test.cc:5:24: required by substitution of ‘template<int d> using e = decltype (b<d>) [with int d = 1]’ test.cc:6:4: required from here test.cc:3:19: internal compiler error: in tsubst_copy, at cp/pt.c:16425 3 | [](auto... c) { [](a<c>...) {}; }; | ^~~~~~~~~~~~~~ 0x7f76079c809a __libc_start_main ../csu/libc-start.c:308 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <file:///usr/share/doc/gcc-10/README.Bugs> for instructions. ```