@@ -44,6 +44,14 @@ OPTIONS
<directory>::
The repository to sync from.
+ENVIRONMENT
+-----------
+
+`GIT_PROTOCOL`::
+ Internal variable used for handshaking the wire protocol. Server
+ admins may need to configure some transports to allow this
+ variable to be passed. See the discussion in linkgit:git[1].
+
SEE ALSO
--------
linkgit:gitnamespaces[7]
@@ -894,6 +894,21 @@ for full details.
Contains a colon ':' separated list of keys with optional values
'key[=value]'. Presence of unknown keys and values must be
ignored.
++
+Note that servers may need to be configured to allow this variable to
+pass over some transports. It will be propagated automatically when
+accessing local repositories (i.e., `file://` or a filesystem path), as
+well as over the `git://` protocol. For git-over-http, it should work
+automatically in most configurations, but see the discussion in
+linkgit:git-http-backend[1]. For git-over-ssh, the ssh server may need
+to be configured to allow clients to pass this variable (e.g., by using
+`AcceptEnv GIT_PROTOCOL` with OpenSSH).
++
+This configuration is optional. If the variable is not propagated, then
+clients will fall back to the original "v0" protocol (but may miss out
+on some performance improvements or features). This variable currently
+only affects clones and fetches; it is not yet used for pushes (but may
+be in the future).
`GIT_OPTIONAL_LOCKS`::
If set to `0`, Git will complete any requested operation without
The v2 protocol requires that the GIT_PROTOCOL environment variable gets passed around, but we don't have any documentation describing how this is supposed to work. In particular, we need to note what server admins might need to configure to make things work. The definition of the GIT_PROTOCOL variable is probably the best place for this, since: - we deal with multiple transports (ssh, http, etc). Transport-specific documentation (like the git-http-backend bits added in the previous commit) are helpful for those transports, but this gives a broader overview. Plus we do not have a specific transport endpoint program for ssh, so this is a reasonable place to mention it. - the server side of the protocol involves multiple programs. For now, upload-pack is the only endpoint which uses GIT_PROTOCOL, but that will likely expand in the future. We're better off with a central discussion of what the server admin might need to do. However, for discoverability, this patch adds a pointer from upload-pack's documentation. Signed-off-by: Jeff King <peff@peff.net> --- Documentation/git-upload-pack.txt | 8 ++++++++ Documentation/git.txt | 15 +++++++++++++++ 2 files changed, 23 insertions(+)