The solution, use the revision attribute in your module set file:

 <repository type=”git” name=”git.freedesktop.org”   href=”git://anongit.freedesktop.org/”/>
 <branch repo=”git.freedesktop.org”    module=”~benjsc/xorg/proto/compositeproto” checkoutdir=”xorg/proto/compositeproto” revision=”ir” />

This checks out the ir branch of the repo: git://anongit.freedesktop.org/~benjsc/xorg/proto/compositeproto

For those looking at the jhbuild code, you can see the fun with the dropped argument:

class GitRepository

…

def branch(self, name, module = None, subdir=”", checkoutdir = None,
revision = None, tag = None):
if name in self.config.branches:
module = self.config.branches[name]
if not module:
raise FatalError(_(‘branch for %s has wrong override, check your .jhbuildrc’) % name)
else:
if module is None:
module = name
module = urlparse.urljoin(self.href, module)
return GitBranch(self, module, subdir, checkoutdir, revision, tag)

class GitBranch(Branch):
“”"A class representing a GIT branch.”"”

def __init__(self, repository, module, subdir, checkoutdir=None, branch=None, tag=None):
Branch.__init__(self, repository, module, checkoutdir)
self.subdir = subdir
self.branch = branch
self.tag = tag

So Where revision go?

Here’s the url redirect list in case someone else wants to use cgit over gitweb (highly recommended)

<VirtualHost *:80>
        ServerName gitweb2.freedesktop.org
        ServerAdmin sitewranglers@freedesktop.org

        CustomLog /var/log/apache2/gitweb.freedesktop.org-access.log combined
        ErrorLog /var/log/apache2/gitweb.freedesktop.org-error.log

        #
        # Redirects mapping gitweb -> cgit
        #
        # Gitweb uses get targets seperated by ;
        #
        # /?...;...;...
        #
        # p = Project
        # a = action ( blob, blob_plain, blobdiff, commitdiff, commit, shortlog, summary, tree, log, tag, history, rss)
        # h = SHA Hash
        # o = sort order
        # hb= SHA Hash Tree Base
        # hp= ?
        # pg= page
        # f= file/dir
        #
        # Cgit uses the following:
        #
        # /project/action/?...
        #
        # action ( commit, log, diff, tree, tag, patch  )
        #
        # id = SHA Hash
        # id2 = SHA Hash
        # h = head
        #
        # Translation rules
        #
        # Project is a straight redirect
        # ---
        # /?p=([^.]+).git;       http://cgit.freedesktop.org/$1/
        #
        # Action requires a mapping
        # ---
        # a=(blob|tree) /tree/
        # a=(blobdiff|commitdiff)       /diff/
        # a=commit      /commit/
        # a=(summary)   /
        # a=(shortlog|log|history)      /log/
        # a=tag         /tag/
        # a=blob_plain  /blob/
        # a=rss    ?No CGIT Equivilant?
        #
        # Targets require mapping
        # ---
        # h=([^;]+)     id=$1
        # f=([^;]+)     /$1
        # hb=([^;]+)    id2=$1
        # hp([^;]+      id=$1
        #
        # Now putting it all together
        #
        RewriteEngine On
        #RewriteLog /tmp/rewrite.log
        #RewriteLogLevel 5
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=blob;h=([^;]+);hb=([^;]+);f=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/tree/%5?id=%3;id2=%4 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=blob;hb=([^;]+);f=([^;]+)
        RewriteRule ^/$  http://cgit.freedesktop.org/%1/tree/%4?id=%3 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=tree;h=([^;]+);hb=([^;]+);f=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/tree/%5?id=%4 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=tree;h=([^;]+);hb=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/tree/?id=%4 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=tree;hb=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/tree/?id=%3 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=tree
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/tree/? [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=blobdiff;h=([^;]+);hp=([^;]+);hb=([^;]+);f=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/diff/%6?id2=%4;id=%3;id3=%5 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=commitdiff;h=([^;]+);hp=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/diff/?id=%4;id2=%3 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=commitdiff;h=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/diff/?id=%3 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=commit;h=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/commit/?id=%3 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=shortlog;h=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/log/?id=%3 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=shortlog
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/log/? [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=log;h=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/log/?id=%3 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=log
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/log? [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=history;h=([^;]+);hb=([^;]+);f=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/log/%5?id=%4 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=history;h=([^;]+);hb=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/log/?id=%4 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=history;hb=([^;]+);f=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/log/%4?id=%3 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=history;hb=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/log/?id=%3 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=tag;h=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/tag/?id=%4 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=blob_plain;h=([^;]+);f=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/blob/%4?id=%3 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=blob_plain;f=([^;]+)
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/blob/%4 [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=rss
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/atom? [R,L,NE]
        RewriteCond %{query_string} p=([^.]+)(\.git)*;a=summary
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/? [R,L,NE]
        #
        # Fail safes incase nothing above matches, try at least to put the person in the project, els root of cgit
        RewriteCond %{query_string} p=([^.]+)(\.git)*.*
        RewriteRule ^/$ http://cgit.freedesktop.org/%1/? [R,L,NE]
        RewriteRule ^.* http://cgit.freedesktop.org/ [R,L,NE]
</VirtualHost>