Comment 1 for bug 93854

Even worse: If a tag actually exists in the branch you are checking out from, checkout fails immediately.

radix@haruko ~/test% mkdir a
radix@haruko ~/test% cd a
radix@haruko ~/test/a% bzr init --format=dirstate-tags
radix@haruko ~/test/a% bzr commit -m 'unchanged' --unchanged
Committed revision 1.
radix@haruko ~/test/a% cd ..
radix@haruko ~/test% bzr checkout a c
radix@haruko ~/test% rm -rf c
radix@haruko ~/test% cd a
radix@haruko ~/test/a% bzr tag what
Created tag what.
radix@haruko ~/test/a% cd ..
radix@haruko ~/test% bzr checkout a c
bzr: ERROR: Tags not supported by BzrBranch5('file:///home/radix/test/c/'); you may be able to use bzr upgrade.