Git – How to git-svn clone the last n revisions from a Subversion repository



How do you create a shallow copy with git-svn from a Subversion repository, e.g. how do you pull only the last three revisions?

The git clone command can get the last n revisions from a Git repository if you use the option --depth, i.e. you get a shallow copy of the repository. Example:

git clone --depth 3 git://some/repo myshallowcopyrepo

Is there a similar option for git-svn?

My discoveries so far

So far I've only found the -rN option where N is the revision to pull. Example:

git svn clone -rN svn://some/repo

According to the documentation there is the possibility to use -r$REVNUMBER:HEAD. I tried the following to get the last 3 revisions which returned an error message.

$ git svn clone --prefix=svn/ -s -rHEAD~3:HEAD http://some/svn/repo .
revision argument: HEAD~3:HEAD not understood by git-svn

So I replaced HEAD~3 with the actual number of the third but last revision 534. That worked, but that requires me to first figure out the revision number of the third but last commit.

$ git svn clone --prefix=svn/ -s -r534:HEAD http://some/svn/repo .




Best Solution

You've already discovered the simplest way to specify a shallow clone in Git-SVN, by specifying the SVN revision number that you want to start your clone at ( -r$REV:HEAD).

For example: git svn clone -s -r1450:HEAD some/svn/repo

Git's data structure is based on pointers in a directed acyclic graph (DAG), which makes it trivial to walk back n commits. But in SVN ( and therefore in Git-SVN) you will have to find the revision number yourself.