Hi Peng. Read the link you provided again. xmalloc is not an alternative version of malloc. It's just a common wrapper function around malloc. You can go and see for yourself, the definition is here: http://git.savannah.gnu.org/cgit/bash.git/tree/xmalloc.c#n97
If you want the rest of the commands execute properly, then make sure that there's enough memory in the system, and remove artificial restrictions (ulimit -v?). There's no trick here, and certainly no bug in bash.
