hg up <branch_name> not changing to the named branch

Question

My mercurial repository was created using a migration of a subversion repository. All else worked fine, except there is one named branch that I cannot update to ...after hg update it still shows the branch as 'default' in hg summary.

The resulting problem is that I am unable to close this old branch (since hg still thinks it is on default)...the files are getting changes as the hg up 1.6 shows

$ $ hg branches
default                     3456:502e03ae682b
1.6                         3080:4518f08ac918

$ hg up 1.6
553 files updated, 0 files merged, 1158 files removed, 0 files unresolved

$ hg sum
parent: 466:76362d78806a 1.6
   Updated profile and route
branch: default
commit: (clean)
update: 1909 new changesets (update)
mq:     3 unapplied

Answer 1

rev 466 has a tag 1.6:

parent: 466:76362d78806a 1.6

Tags are chosen over branches, so update to the correct node using the local revision or hash instead:

hg update 3080  
hg update 4518f08ac918

You can also remove the 1.6 tag and give it another name to reduce confusion:

hg tag --remove 1.6
hg tag -r 466 1_6