* Package:    dev-cpp/tree-2.81
 * Repository: gentoo
 * Maintainer: sci@gentoo.org
 * USE:        abi_x86_64 amd64 elibc_glibc kernel_linux userland_GNU
 * FEATURES:   network-sandbox preserve-libs sandbox splitdebug userpriv usersandbox

>>> Unpacking source...
>>> Unpacking tree-2.81.tar.gz to /var/tmp/portage/dev-cpp/tree-2.81/work
>>> Source unpacked in /var/tmp/portage/dev-cpp/tree-2.81/work
>>> Preparing source in /var/tmp/portage/dev-cpp/tree-2.81/work/tree-2.81/src ...
 * Applying tree-2.81-test.patch ...
 [ ok ]
>>> Source prepared.
>>> Configuring source in /var/tmp/portage/dev-cpp/tree-2.81/work/tree-2.81/src ...
>>> Source configured.
>>> Compiling source in /var/tmp/portage/dev-cpp/tree-2.81/work/tree-2.81/src ...
make -j 1 
x86_64-pc-linux-gnu-g++ -pipe -march=native -fno-diagnostics-color  -Og -g  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0  test_tree.cc   -o test_tree
In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include/g++-v11/set:60,
                 from tree.hh:35,
                 from test_tree.cc:21:
/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include/g++-v11/bits/stl_tree.h: In instantiation of ‘static const _Key& std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_S_key(std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_Const_Link_type) [with _Key = tree_node_<std::__cxx11::basic_string<char> >*; _Val = tree_node_<std::__cxx11::basic_string<char> >*; _KeyOfValue = std::_Identity<tree_node_<std::__cxx11::basic_string<char> >*>; _Compare = tree<std::__cxx11::basic_string<char> >::compare_nodes<std::less<std::__cxx11::basic_string<char> > >; _Alloc = std::allocator<tree_node_<std::__cxx11::basic_string<char> >*>; std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_Const_Link_type = const std::_Rb_tree_node<tree_node_<std::__cxx11::basic_string<char> >*>*]’:
/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include/g++-v11/bits/stl_tree.h:2100:44:   required from ‘std::pair<std::_Rb_tree_node_base*, std::_Rb_tree_node_base*> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_get_insert_equal_pos(const key_type&) [with _Key = tree_node_<std::__cxx11::basic_string<char> >*; _Val = tree_node_<std::__cxx11::basic_string<char> >*; _KeyOfValue = std::_Identity<tree_node_<std::__cxx11::basic_string<char> >*>; _Compare = tree<std::__cxx11::basic_string<char> >::compare_nodes<std::less<std::__cxx11::basic_string<char> > >; _Alloc = std::allocator<tree_node_<std::__cxx11::basic_string<char> >*>; std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::key_type = tree_node_<std::__cxx11::basic_string<char> >*]’
/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include/g++-v11/bits/stl_tree.h:2149:4:   required from ‘std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_insert_equal(_Arg&&) [with _Arg = tree_node_<std::__cxx11::basic_string<char> >* const&; _Key = tree_node_<std::__cxx11::basic_string<char> >*; _Val = tree_node_<std::__cxx11::basic_string<char> >*; _KeyOfValue = std::_Identity<tree_node_<std::__cxx11::basic_string<char> >*>; _Compare = tree<std::__cxx11::basic_string<char> >::compare_nodes<std::less<std::__cxx11::basic_string<char> > >; _Alloc = std::allocator<tree_node_<std::__cxx11::basic_string<char> >*>; std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator = std::_Rb_tree<tree_node_<std::__cxx11::basic_string<char> >*, tree_node_<std::__cxx11::basic_string<char> >*, std::_Identity<tree_node_<std::__cxx11::basic_string<char> >*>, tree<std::__cxx11::basic_string<char> >::compare_nodes<std::less<std::__cxx11::basic_string<char> > >, std::allocator<tree_node_<std::__cxx11::basic_string<char> >*> >::iterator]’
/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include/g++-v11/bits/stl_multiset.h:503:36:   required from ‘std::multiset<_Key, _Compare, _Alloc>::iterator std::multiset<_Key, _Compare, _Alloc>::insert(const value_type&) [with _Key = tree_node_<std::__cxx11::basic_string<char> >*; _Compare = tree<std::__cxx11::basic_string<char> >::compare_nodes<std::less<std::__cxx11::basic_string<char> > >; _Alloc = std::allocator<tree_node_<std::__cxx11::basic_string<char> >*>; std::multiset<_Key, _Compare, _Alloc>::iterator = std::_Rb_tree<tree_node_<std::__cxx11::basic_string<char> >*, tree_node_<std::__cxx11::basic_string<char> >*, std::_Identity<tree_node_<std::__cxx11::basic_string<char> >*>, tree<std::__cxx11::basic_string<char> >::compare_nodes<std::less<std::__cxx11::basic_string<char> > >, std::allocator<tree_node_<std::__cxx11::basic_string<char> >*> >::const_iterator; std::multiset<_Key, _Compare, _Alloc>::value_type = tree_node_<std::__cxx11::basic_string<char> >*]’
tree.hh:1523:15:   required from ‘void tree<T, tree_node_allocator>::sort(tree<T, tree_node_allocator>::sibling_iterator, tree<T, tree_node_allocator>::sibling_iterator, StrictWeakOrdering, bool) [with StrictWeakOrdering = std::less<std::__cxx11::basic_string<char> >; T = std::__cxx11::basic_string<char>; tree_node_allocator = std::allocator<tree_node_<std::__cxx11::basic_string<char> > >]’
test_tree.cc:292:11:   required from here
/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include/g++-v11/bits/stl_tree.h:770:15: error: static assertion failed: comparison object must be invocable as const
  770 |               is_invocable_v<const _Compare&, const _Key&, const _Key&>,
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include/g++-v11/bits/stl_tree.h:770:15: note: ‘std::is_invocable_v<const tree<std::__cxx11::basic_string<char> >::compare_nodes<std::less<std::__cxx11::basic_string<char> > >&, tree_node_<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >* const&, tree_node_<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >* const&>’ evaluates to false
make: *** [<builtin>: test_tree] Error 1
 * ERROR: dev-cpp/tree-2.81::gentoo failed (compile phase):
 *   emake failed
 * 
 * If you need support, post the output of `emerge --info '=dev-cpp/tree-2.81::gentoo'`,
 * the complete build log and the output of `emerge -pqv '=dev-cpp/tree-2.81::gentoo'`.
 * The complete build log is located at '/var/log/portage/dev-cpp:tree-2.81:20210501-233933.log'.
 * For convenience, a symlink to the build log is located at '/var/tmp/portage/dev-cpp/tree-2.81/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/dev-cpp/tree-2.81/temp/environment'.
 * Working directory: '/var/tmp/portage/dev-cpp/tree-2.81/work/tree-2.81/src'
 * S: '/var/tmp/portage/dev-cpp/tree-2.81/work/tree-2.81/src'