Why doesn't http://scm.trinitydesktop.org/scm/git/ respect '--depth 1'

Tim, all,

I am working on build scripts that will individually pull or update the source by pulling code from the git tree. To make this more efficient for building individual modules (and reduce unneeded bandwidth), it is recommended to use the git clone form:

git clone --depth 1 http://scm.trinitydesktop.org/scm/git/whatever

But http://scm.trinitydesktop.org/scm/git/ refuses to allow '--depth 1' to be used in the git clone. Anybody know why? The error received is:

Cloning into 'libart-lgpl'... error: RPC failed; result=22, HTTP code = 500 fatal: The remote end hung up unexpectedly

It works fine without the --depth limitation. What say the 'git' masters?