Converting version control repositories from Bazaar to Git (bzr to git)

Bazaar is great on Windows. Several years later, git's tools for Windows still.... (ahem) are lacking or too commercial. However, official development on it has ended and git is so much more popular now. So I think the time has come to convert all my beloved bzr repositories to git.

First we need note some prerequisites:

• Bazaar
• Git (msysgit flavor)
• Hstart (you could do it without, but the script uses it, as written)
• TortoiseGit (not strictly necessary, but it's my preferred way of using git repositories)

Get all those installed and then we can use the script attached.

The output looks like this:

Found a bzr repository in...
   F:\CodeProjects\ExportPDF-01\

Press [Enter] to open a git shell and continue.

Welcome to Git (version 1.9.4-preview20140929)

Run 'git help git' to display the help index.
Run 'git help <command>' to display help for specific commands.
/f/CodeProjects /f/CodeProjects/ExportPDF-01
/f/CodeProjects/ExportPDF-01

This script creates a git repository from a bzr repository.

Affected directory: ExportPDF-01
                in: /f/CodeProjects/

Initializing git repository in /f/CodeProjects/ExportPDF-01 ...
Initialized empty Git repository in f:/CodeProjects/ExportPDF-01/.git/
Converting...
16:06:28 Calculating the revisions to include ...
16:06:28 Starting export of 3 revisions ...
G:/Programming/Bazaar/plugins\fastimport\exporter.py:557: DeprecationWarning:
bzrlib.revisiontree.InventoryRevisionTree._get_inventory was deprecated in version 2.5.0.

16:06:28 Exported 3 revisions in 0:00:00
G:\Programming\Git\libexec\git-core\git-fast-import.exe statistics:
---------------------------------------------------------------------
Alloc'd objects:   5000
Total objects:       65 ( 6 duplicates )
       blobs :       42 ( 5 duplicates    18 deltas of    41 attempts)
       trees :       20 ( 1 duplicates     6 deltas of    20 attempts)
      commits:        3 ( 0 duplicates     0 deltas of     0 attempts)
        tags :        0 ( 0 duplicates     0 deltas of     0 attempts)
Total branches:       1 ( 1 loads     )
      marks:       1024 ( 3 unique    )
      atoms:         38
Memory total:      2294 KiB
       pools:      2098 KiB
     objects:       195 KiB
---------------------------------------------------------------------
pack_report: getpagesize()            =     65536
pack_report: core.packedGitWindowSize =  33554432
pack_report: core.packedGitLimit      = 268435456
pack_report: pack_used_ctr            =        15
pack_report: pack_mmap_calls          =         8
pack_report: pack_open_windows        =         1 /          1
pack_report: pack_mapped              =     36961 /      36961
---------------------------------------------------------------------

Creating .gitignore from .bzrignore...
Cloning repository...
Cloning into 'f:/CodeProjects/ExportPDF-01-clone'...
done.

Creating dummy remote folder (locally)...
------------------------------------------------------------------------------

             Total    Copied   Skipped  Mismatch   FAILED    Extras
   Dirs :       34        34         0         0        0         0
  Files :       78        78         0         0        0         0
  Bytes :  264.4 k   264.4 k         0         0        0         0
  Times :  0:00:00   0:00:00                      0:00:00   0:00:00

  Speed :            2820656 Bytes/sec.
  Speed :            161.399 MegaBytes/min.
  Ended : Saturday, November 8, 2014 4:06:29 PM

Fetching into remote folder...
From f:/CodeProjects/ExportPDF-01-tmp
* [new branch] master -> origin/master
Already on 'master'
Your branch is up-to-date with 'origin/master'.

Copying .git from dummy folder back to repository...
cp: `/f/CodeProjects/ExportPDF-01-clone/.git/objects/pack/pack-d642dfcb49971e8a979d2f266f4f67dc0247e32b.idx' and `/f/CodeProjects/ExportPDF-01/.git/objects/pack/pack-d642dfcb49971e8a979d2f266f4f67dc0247e32b.idx' are the same file
cp: `/f/CodeProjects/ExportPDF-01-clone/.git/objects/pack/pack-d642dfcb49971e8a979d2f266f4f67dc0247e32b.pack' and `/f/CodeProjects/ExportPDF-01/.git/objects/pack/pack-d642dfcb49971e8a979d2f266f4f67dc0247e32b.pack' are the same file

Cleaning up...
error: tag 'origin/HEAD' not found.

Error at git
Continuing from next operation...

error: tag 'origin/master' not found.

Error at git
Continuing from next operation...

Press [Enter] to continue

The errors at the end can be ignored. You'll want to check the new git repository before deleting the bzr folder.