rubinius/rubinius — comment on commit 9cb38002f2b0c2c4c67e7efc85a4877b728b5109
File:  line 0
By jfirebaugh:

The specs pass on MRI compiled against non-glibc standard C library (e.g. on darwin). They fail on MRI compiled against glibc.

But I'm starting to think these aren't great specs for a number of reasons:

* glibc is buggy
* MRI is buggy: http://redmine.ruby-lang.org/issues/5713
* Some implementations (JRuby) do not follow MRI, and actually try to calculate 2 ** bignum

What these add up to is that effectively Ruby has no consistent behavior for Bignum exponents. :(