I\'m struggling for a number of hours now with the --ignore-paths option to git-svn, in an attempt to fetch only certain tags from a large repository.
I want to start
I have been experiencing strange problems with --ignore-paths too. git-svn seems to ignore the entire regexp in some cases. I have seen the same regexp working on repos 1 and ignored on repos 2, where both repos have the same file structure, but different history.
Although I don't see anything wrong with your regexp for your specific tree, I would recommend using the ^ caret at the beginning to specify the ignored paths starting at the root. This might help the rexexp parser speed-up the search and avoid issues where a match could also be found deep inside the trunk for example.
I would use something like --ignore-paths="^tags/Acme-(4|5.[0-4])"