Unset SSH_AUTH_SOCK unless --ssh_allow_agent

It turns out that using SSH_AUTH_SOCK can make ssh connections super
slow to establish in some situations.  Let's remove it unless the user
specifically requests it.

This speeds update_kernel up from ~35 seconds to ~5 seconds on most
Google Engineer's workstations.

TEST=time ./ --remote=zzz --noreboot --ssh_allow_agent
TEST=time ./ --remote=zzz --noreboot

Change-Id: I696e1b318c5864c3d2307cef7517b884d04e145b
Signed-off-by: Douglas Anderson <>
Reviewed-by: Mike Frysinger <>
1 file changed