[Bug c++/96409] New: A lambda with a template parameter list inside the template function using C++20 nested requirements clauses occurs internal compiler error

[hewillk at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96409

            Bug ID: 96409
           Summary: A lambda with a template parameter list inside the
                    template function using C++20 nested requirements
                    clauses occurs internal compiler error
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hewillk at gmail dot com
  Target Milestone: ---

Created attachment 48977
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48977&action=edit
the preprocessed file

Using built-in specs.
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ignoring duplicate directory "/usr/local/include"
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-fpreprocessed main.ii -fPIC -quiet -dumpbase main.cpp
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main.s
GNU C++17 (Homebrew GCC 10.1.0) version 10.1.0 (x86_64-apple-darwin17)
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GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C++17 (Homebrew GCC 10.1.0) version 10.1.0 (x86_64-apple-darwin17)
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GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: b1074358e29f54f1a357a06623845700
main.cpp: In instantiation of 'void f(T) [with T = std::vector<int>]':
main.cpp:14:23:   required from here
main.cpp:7:39: internal compiler error: in dependent_type_p, at cp/pt.c:26343
    7 |     if constexpr (requires { requires std::same_as<U,
std::vector<typename U::value_type>>; });
      |                             
~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
libbacktrace could not find executable to open
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