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IMPORTANT NOTE: although this page has a "gitolite.com" URL, this is not about gitolite. That's just an artifact of "sitaramc.github.com" being translated to "gitolite.com" and so ALL my git related stuff gets carried over. Gitolite documentation has another /gitolite in the URL, so you can tell. My apologies for this confusion.

converting CVS to git

Update 2009-10-08: It has been pointed out that cvsimport, which I recommend against using below, can do incremental imports. If this is important to you (it wasn’t, to me, and it never will be), then this document is probably no use to you. Sorry…

First: do NOT use the builtin git cvsimport unless your repository is very simple and linear. Problems I had using it on a moderately complex repo include missing tags, branches grafted to the wrong place (by comparing with a --simplify-by-decoration tree later), missing commits (which is what originally made me start investigating), and even missing files in the root of the repo!!

It’s been too long since I last used CVS to figure this out, and cvs2svn seemed to deal with a lot more nuances, so I used that instead.

1 step 1 – make a dump file

download cvs2svn version 2.1 or higher from somewhere within https://cvs2svn.tigris.org/cvs2git.html. DO NOT BE DISTRACTED BY THE MISLEADING REFERENCES TO A MYTHICAL cvs2git COMMAND IN THAT PAGE :) As of the time I tried this, it didn’t exist. Maybe now it does…
expand it somewhere, and cd there
in there, create an options file from the original, like shown in the patch at the end of this file (change accordingly of course; this diff only shows where you should make the changes, not what)

IMPORTANT WARNING

DO NOT USE the test-data/main-cvsrepos/cvs2svn-git.options file as a starting point. Though the intermediate files were about 3X smaller when I used it, there were lots of inaccuracies w.r.t the $id type stuff, and for some older tags whole files were missing, compared to the corresponding CVS checkout. The -inline version seems to work fine; no errors on any of the 30 or so tags I checked on a project that had about 5 years of work in CVS.
run
```
./cvs2svn --options=my.c2soptions
```
when it completes, check the cvs2svn-tmp directory for a rather large file called git-dump.dat

2 step 2 – import into git

make an empty directory, cd to it, git init, then run
```
cat ~-/cvs2svn-tmp/git-dump.dat | git fast-import
```
if you used the non-inline options file, or wanted to test that as well, there would be two files in the cvs2svn-tmp directory, and the command would now be:
```
cat ~-/cvs2svn-tmp/git-{blob,dump}.dat | git fast-import
```

3 Appendix

These are the changes I made to the options file:

diff --git 1/test-data/main-cvsrepos/cvs2svn-git-inline.options 2/my.c2soptions.inline
index 635f9cd..a5a4018 100644
--- 1/test-data/main-cvsrepos/cvs2svn-git-inline.options
+++ 2/my.c2soptions.inline
@@ -39,7 +39,7 @@ ctx.cross_branch_commits = False
 # record the original author (for example, the creation of a branch).
 # This should be a simple (unix-style) username, but it can be
 # translated into a git-style name by the author_transforms map.
-ctx.username = 'cvs2svn'
+ctx.username = 'someone'

 # CVS uses unix login names as author names whereas git requires
 # author names to be of the form "foo <bar>".  The default is to set
@@ -59,7 +59,7 @@ author_transforms={

     # This one will be used for commits for which CVS doesn't record
     # the original author, as explained above.
-    'cvs2svn' : ('cvs2svn', 'admin@example.com'),
+    'someone' : ('someone', 'someone@my.company.com'),
     }

 # This is the main option that causes cvs2svn to output to git rather
@@ -115,7 +115,7 @@ run_options.add_project(
     # The path to the part of the CVS repository (*not* a CVS working
     # copy) that should be converted.  This may be a subdirectory
     # (i.e., a module) within a larger CVS repository.
-    r'test-data/main-cvsrepos',
+    r'../cvsroot/myproj',

     # See cvs2svn-example.options for more documention about symbol
     # transforms that can be set using this option.