Create a users file (i.e. users.txt) for mapping SVN users to Git:
user1 = First Last Name <email@address.com>
user2 = First Last Name <email@address.com>
...
You can use this one-liner to build a template from your existing SVN repository:
svn log -q | awk -F '|' '/^r/ {gsub(/ /, "", $2); sub(" $", "", $2); print $2" = "$2" <"$2">"}' | sort -u > users.txt
SVN will stop if it finds a missing SVN user, not in the file. But after that, you can update the file and pick up where you left off.
Now pull the SVN data from the repository:
git svn clone --stdlayout --no-metadata --authors-file=users.txt svn://hostname/path dest_dir-tmp
This command will create a new Git repository in dest_dir-tmp and start pulling the SVN repository. Note that the "--stdlayout" flag implies you have the common "trunk/, branches/, tags/" SVN layout. If your layout differs, become familiar with --tags, --branches, --trunk options (in general git svn help).
All common protocols are allowed: svn://, http://, https://. The URL should target the base repository, something like http://svn.mycompany.com/myrepo/repository. The URL string must not include /trunk, /tag or /branches.
Note that after executing this command it very often looks like the operation is "hanging/frozen", and it's quite normal that it can be stuck for a long time after initializing the new repository. Eventually, you will then see log messages which indicate that it's migrating.
Also note that if you omit the --no-metadata flag, Git will append information about the corresponding SVN revision to the commit message (i.e. git-svn-id: svn://svn.mycompany.com/myrepo/<branchname/trunk>@<RevisionNumber> <Repository UUID>)
If a user name is not found, update your users.txt file then:
cd dest_dir-tmp
git svn fetch
You might have to repeat that last command several times, if you have a large project until all of the Subversion commits have been fetched:
git svn fetch
When completed, Git will checkout the SVN trunk into a new branch. Any other branches are set up as remotes. You can view the other SVN branches with:
git branch -r
If you want to keep other remote branches in your repository, you want to create a local branch for each one manually. (Skip trunk/master.) If you don't do this, the branches won't get cloned in the final step.
git checkout -b local_branch remote_branch
# It's OK if local_branch and remote_branch are the same names
Tags are imported as branches. You have to create a local branch, make a tag and delete the branch to have them as tags in Git. To do it with tag "v1":
git checkout -b tag_v1 remotes/tags/v1
git checkout master
git tag v1 tag_v1
git branch -D tag_v1
Clone your GIT-SVN repository into a clean Git repository:
git clone dest_dir-tmp dest_dir
rm -rf dest_dir-tmp
cd dest_dir
The local branches that you created earlier from remote branches will only have been copied as remote branches into the newly cloned repository. (Skip trunk/master.) For each branch you want to keep:
git checkout -b local_branch origin/remote_branch
Finally, remove the remote from your clean Git repository that points to the now-deleted temporary repository:
git remote rm origin
Best Answer
As mentioned here (ibm) and in this thread, there is no direct tool to import SVN data to ClearCase.
That means a custom script setting your SVN workspace to relevant milestone, and then clearfsimport those into a ClearCase view with a "proper" config spec (i.e. "configuration specification").
By proper, I mean a ClearCase view importing into the relevant ClearCase branch the different copies of Subversion files located into 'branch directories'. And then importing in the right order the 'tags' (still copies in the SVN repo) in the ClearCase import view, with a label set right after that kind of import.
So the main 'gotcha' is to blindly import the all SVN structure: that would result in actual directories which should not be present at all in ClearCase, since branches and tags are first-class citizen with this tool, and not 'cheap copy' like in SVN.
A good script to start with (and to adapt of course) would be svn2git which does detect SVN branches and tag, and try to import the content of those 'directories' into git, (but could also import them into ClearCase, through the right system call to the 'clearfsimport' command').
Since the import of a single revision can be fairly long, a realistic approach would be to limit the script to only import:
When importing branches, that means creating the brtype, and then setting a label (a starting point), finally changing the config spec in order to get the following selection rules:
The important point is to have an end result without the directories representing branch and tag present in SVN.
From there, you will be able to move/rename the main directories into whatever structure you want, like the one suited for UCM component declaration (if you want to use UCM).