LD_LIBRARY_PATH is unset automatically for set-group-id binaries.
ssh-agent is setgid ssh to prevent ptrace attacks (i.e. if it were not setgid, an attacker who had managed to compromise your account could also bypass passphrase protection on your key by ptracing a running ssh-agent). I'm afraid I have no intention of disabling this protection.
LD_LIBRARY_PATH is unset automatically for set-group-id binaries.
ssh-agent is setgid ssh to prevent ptrace attacks (i.e. if it were not setgid, an attacker who had managed to compromise your account could also bypass passphrase protection on your key by ptracing a running ssh-agent). I'm afraid I have no intention of disabling this protection.