rustfmt: stack overflow error

I met a stackoverflow error when using rustfmt-nightly (cargo fmt’s result doesn’t include the last abort message):

$ rustfmt core/src/lib.rs

thread 'main' has overflowed its stack
fatal runtime error: stack overflow
[2]    28653 abort      rustfmt core/src/lib.rs

$ rustfmt --version
0.3.3-nightly ( )

Unfortunately, I don’t know how to get the internal backtrace.