git archive can work with a server with git protocol support (i.e. git server, smart-http and ssh server). In your case, either your git is too old, or the server is dumb http server (normal http server, without “smart” git support). You need to clone the repository and archive from there.
Updated Answer As @user3159253 stated in comments of this answer : git garbage-collects commits which aren’t referenced, directly or indirectly, by a named reference (branch, tag, etc). That is why it is important to leave a reference to a freezed branch. You can tag the tip of the branch by archiving it, and then delete …
The Short Answer (TL;DR) “Tree-ish” is a term that refers to any identifier (as specified in the Git revisions documentation) that ultimately leads to a (sub)directory tree (Git refers to directories as “trees” and “tree objects”). In the original poster’s case, foo is a directory that he wants to specify. The correct way to specify …
Probably the simplest way to achieve this is with git archive. If you really need just the expanded tree you can do something like this. git archive master | tar -x -C /somewhere/else Most of the time that I need to ‘export’ something from git, I want a compressed archive in any case so I …