circle segfaults when given input from stdin

[nithrill]

The following commands cause a segfault:

$ echo | circle -E -dM -
Segmentation fault

$ echo "" | circle -E -dM -
Segmentation fault

$ echo "int main() {}" | circle -E -dM -
Segmentation fault

$ circle -E -dM - <<EOF
> int main() {}
> EOF
Segmentation fault

The expected result should be the same as executing:

$ circle -E -dM empty.cpp
#define __circle_build__ 205
<... snip ...>
#define _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED

where empty.cpp is just empty (created in bash via > empty.cpp)