I have a server running gitosis (installed from the package manager) on debian lenny. I am able to perform all operations from my linux mint laptop, but from my Mac running an up-to-date Snow Leopard gives me the following error:

mica@waste Desktop$ git clone [email protected]:Poems.git
Initialized empty Git repository in /Users/micas/Desktop/Poems/.git/
ERROR:gitosis.serve.main:Repository read access denied
fatal: The remote end hung up unexpectedly
mica@waste Desktop$ ssh -v [email protected]
OpenSSH_5.2p1, OpenSSL 0.9.8l 5 Nov 2009
debug1: Reading configuration data /etc/ssh_config
debug1: Applying options for *
debug1: Connecting to 192.168.0.156 [192.168.0.156] port 22.
debug1: Connection established.
debug1: identity file /Users/micas/.ssh/identity type -1
debug1: identity file /Users/micas/.ssh/id_rsa type 1
debug1: identity file /Users/micas/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.1p1 Debian-5
debug1: match: OpenSSH_5.1p1 Debian-5 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.2
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host '192.168.0.156' is known and matches the RSA host key.
debug1: Found key in /Users/mica/.ssh/known_hosts:5
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: publickey
debug1: Offering public key: /Users/mica/.ssh/id_rsa
debug1: Remote: Forced command: gitosis-serve mica@waste
debug1: Remote: Port forwarding disabled.
debug1: Remote: X11 forwarding disabled.
debug1: Remote: Agent forwarding disabled.
debug1: Remote: Pty allocation disabled.
debug1: Server accepts key: pkalg ssh-rsa blen 277
debug1: Remote: Forced command: gitosis-serve micas@waste
debug1: Remote: Port forwarding disabled.
debug1: Remote: X11 forwarding disabled.
debug1: Remote: Agent forwarding disabled.
debug1: Remote: Pty allocation disabled.
debug1: Authentication succeeded (publickey).
debug1: channel 0: new [client-session]
debug1: Requesting [email protected]
debug1: Entering interactive session.
debug1: Requesting authentication agent forwarding.
PTY allocation request failed on channel 0
ERROR:gitosis.serve.main:Need SSH_ORIGINAL_COMMAND in environment.
                                                                  debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug1: client_input_channel_req: channel 0 rtype [email protected] reply 0
debug1: channel 0: free: client-session, nchannels 1
Connection to 192.168.0.156 closed.
Transferred: sent 2544, received 2888 bytes, in 0.1 seconds
Bytes per second: sent 29642.1, received 33650.3
debug1: Exit status 1

Extensive googling of the error isn't returning much-- I changed the /etc/sshd_config file on my Mac as per http://www.schmidp.com/2009/06/23/enable-ssh-agent-key-forwarding-on-snow-leopard/. I still get the same error.