got error when making arm cross compiler by RSB

[2654577874]

Hi,

I got error report when use this command in RSB.my host is ubuntu 12.04,RSB  git branch is  master.
command is:
 ../source-builder/sb-set-builder --prefix=/home/w/development/rtems/4.9  4.9/rtems-arm

error report:

script: 72: # Default environment set up.
script: 73: LANG=C
script: 74: export LANG
script: 75: unset DISPLAY || :
script: 76: umask 022
script: 77: cd "/home/w/development/rtems/rsb/rtems-source-builder/rtems/build/arm-rtems4.9-kernel-4.12 (29819a271950)-1"
script: 78: echo "=> arm-rtems4.9-kernel-4.12 (29819a271950)-1:"
script: 79: echo "==> %prep:"
script: 80: source_dir_rtems="rtems-4.12 (29819a271950)"
source setup: arm-rtems4.9-kernel-4.12 (29819a271950)-1: source rtems -q -c -n arm-rtems4.9-kernel-4.12 (29819a271950)-1-4.12 (29819a271950)
making dir: /home/w/development/rtems/rsb/rtems-source-builder/rtems/sources
download: ftp://ftp.rtems.org/pub/rtems/releases/4.9/4.12 -> sources/rtems-4.12 (29819a271950).tar.bz2
download: ftp://ftp.rtems.org/pub/rtems/releases/4.9/4.12 -> sources/rtems-4.12 (29819a271950).tar.bz2
download: ftp://ftp.rtems.org/pub/rtems/releases/4.9/4.12: error: <urlopen error [Errno -5] No address associated with hostname>
error: downloading (29819a271950).tar.bz2: all paths have failed, giving up


it seems that I went a wrong place to get tarball, anyone know how can I fix it ?


Best regards,

Xinyuan