NB: patches to integrate this information into the manual proper would be gratefully accepted

Renaming Monotone Branches

Branch renaming is not natively supported or encouraged in monotone, but if you feel you really need to do it, it is possible. Keep in mind, monotone is a distributed version control system. This means that even though you may rename a branch locally, unless every other database with that branch performs the same operation, the old branch will return the next time you do a pull or sync operation.

The following commands can be used to rename a branch in your local copy. I would advise backing up the database before performing any of these operations.

for REV in `mtn automate select b:OLDBRANCH`; do
   mtn cert $REV branch NEWBRANCH
done
mtn db kill_branch_certs_locally OLDBRANCH

If your branch names contain '/' characters, either escape the '/' characters or use the shell snippet below.

for REV in `mtn db execute "SELECT id FROM revision_certs WHERE name = 'branch' AND value LIKE 'OLDBRANCH'" | grep ^[0123456789abcdef]*$`; do
   mtn cert $REV branch NEWBRANCH
done
mtn db kill_branch_certs_locally OLDBRANCH

Basically this issues new branch certs for the branch you specifiy, and then the old branch certs are deleted. Be sure that the rename was successful (check with mtn log, mtn list branches, etc.) before issuing the mtn db kill_branch_certs_locally command.

Note: You will have to enter your password once for every branch cert. To avoid this you can create a password hook in your .monotonerc file or use yes PASSWORD | mtn cert..., although that is not very secure (users can use ps aux or read your .bash_history to get your password). The ssh-agent integration available since mtn 0.34 is probably a solution to this, too.

CraigLennox: These may fail with an "argument list too long" error if the branch contains a very large number (i.e. thousands) of revisions. You can get around that limitation by replacing instances of

for REV in `mtn cmd args...`; do

with

mtn cmd args... | while read REV; do

Branch Renaming Script

Here is a script that can be used to rename branches, including names branch with / characters in them. Be sure to backup your database before using it. You must set the MTN_DB environment variable to the location of your database.

#!/bin/bash

set -e

if [ -z "$1" -o -z "$2" ]; then
        echo "Usage: $0 old.branch.name new.branch.name" 1>&2
        exit 1
fi

if [ -z "$MTN_DB" ]; then
        echo "MTN_DB not set" 1>&2
        exit 1
fi

# use sed here to escape '/' characters
OLD=$(echo $1 |  sed -e '{s/\//\\\//g}')
NEW=$2

for REV in `mtn -d $MTN_DB automate select b:$OLD`; do
        mtn -d $MTN_DB cert $REV branch $NEW
done
mtn -d $MTN_DB db kill_branch_certs_locally $1

Using A Ruby Shell To Manipulate Branches

Using a ruby (or perl or python) shell can be a very convienient way to solve problems.

% irb
irb> certs=`mtn automate select b:com.kiatoa.matt.rails`.split
=> ["0c597195698413293cc49691b0301b7f41af8be8", "17212d1b8058418432cf964754a2b08e16701e78", .... ]
irb> illegal="b715c|af49e0|7d7f"
irb> certs.each do |c| 
         if ! c.match(/^#{illegal}/)
              system "mtn cert #{c} branch com.kiatoa.matt.rails2"
         end
     end

This allowed me to make a new branch with a head removed that I couldn't figure out how any other way to resolve.