Created attachment 33529 [details]
Preprocessed source

The following file gives a "confused by earlier errors, bailing out" error message, with no previous errors printed, when compiled with -fsanitize=undefined:

$ cat confused.cpp
#include <memory>
#include <map>

int
main()
{
  std::unique_ptr<int> ptr{new int};
  std::map<int, std::unique_ptr<int>> map;
  map.insert({0, std::move(ptr)});
  return 0;
}
$ g++ -std=c++11 -fsanitize=undefined confused.cpp
‘
/usr/include/c++/4.9.1/ext/new_allocator.h:120: confused by earlier errors, bailing out

Without the -fsanitize=undefined, it points to the actual error, which is fixed by using std::make_pair instead of a braced initializer as the argument to insert().