Permission denied (public key) when running ./update with git on Nios2 Linux

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hi, I am using Centos 6.4 on 64 bits OS and I follow the instruction at http://www.alterawiki.com/wiki/install_nios_ii_linux, I got the following error when running [/home/hippo/nios2-linux]# ./update

update binutils..

Already up-to-date.

update gcc3..

Already up-to-date.

update linux-2.6..

Already up-to-date.

update toolchain-build..

Already up-to-date.

update toolchain-mmu..

Already up-to-date.

update uClibc..

Already up-to-date.

update elf2flt..

Already up-to-date.

update insight..

Already up-to-date.

update u-boot..

Already up-to-date.

update uClinux-dist..

Already up-to-date.

update boards..

Already up-to-date.

update openip..

Permission denied (publickey).

fatal: The remote end hung up unexpectedly

update tools..

Your configuration specifies to merge with the ref 'master'

from the remote, but no such ref was fetched.

May I know how can I get over this? Is it necessary for openip and tools to get update?

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Hi, I manage to resolve the issue by running git clone manually. git clone git://sopc.et.ntust.edu.tw/git/boards.git

git clonegit://sopc.et.ntust.edu.tw/git/openip.git

git clonegit://sopc.et.ntust.edu.tw/git/tools.git

I manage to resolve it by manually running inn terminal window:

git clone git://sopc.et.ntust.edu.tw/git/boards.git

git clone git://sopc.et.ntust.edu.tw/git/openip.git

git clone git://sopc.et.ntust.edu.tw/git/tools.git