The installation script you used seems to use the bzr-colo plugin to manage colocated branches.
The bzr-colo
manual indicates that because absolute pathnames are used to store references to branches, when a colocated workspace is moved on disk, the link from the checkout to the current branch gets broken.
This can theoretically be fixed by running bzr colo-fixup
in the broken branch directory, however it does not seem work very often (in my experience).
In that case the manual recommends running this command to re-force a branch switch:
bzr switch --force .bzr/branches/<current branch name>
According to the output of your commands, this should be:
bzr switch --force .bzr/branches/origin/trunk
for you.
You do not even need to edit the .bzr/branch/location
first, as it will be correct after the switch. This has always fixed the situation for me.