I think there is only one failing doctest:

sage -t --long -force_lib devel/sage/sage/interfaces/sage0.py
**********************************************************************
File "/Users/palmieri/Desktop/Sage_stuff/sage_builds/12719/sage-5.4.rc3/devel/sage-main/sage/interfaces/sage0.py", \
line 489:
sage: sage0(4).gcd
Expected:
<built-in method gcd of sage.rings.integer.Integer object at 0x...>
Got:
<function gcd>
**********************************************************************

and it should be trivial to fix. I also don't know how serious the issue is. I mean, it would be nice if `4.gcd`

printed more information, but it doesn't seem crucial in any way.