Git Anonymization and Fast Export

resemblance to the originals). The relative makeup of the tree is retained (e.g., if you have a root tree with 10 files and 3 trees, so will the output), but their names and the contents of the files will be replaced. If you think you have found a git bug, you can start by exporting an anonymized stream of the whole repository: --------------------------------------------------- $ git fast-export --anonymize --all >anon-stream --------------------------------------------------- Then confirm that the bug persists in a repository created from that stream (many bugs will not, as they really do depend on the exact repository contents): --------------------------------------------------- $ git init anon-repo $ cd anon-repo $ git fast-import <../anon-stream $ ... test your bug ... --------------------------------------------------- If the anonymized repository shows the bug, it may be worth sharing `anon-stream` along with a regular bug report. Note that the anonymized stream compresses very well, so gzipping it is encouraged. If you want to examine the stream to see that it does not contain any private data, you can peruse it directly before sending. You may also want to try: --------------------------------------------------- $ perl -pe 's/\d+/X/g' <anon-stream | sort -u | less --------------------------------------------------- which shows all of the unique lines (with numbers converted to "X", to collapse "User 0", "User 1", etc into "User X"). This produces a much smaller output, and it is usually easy to quickly confirm that there is no private data in the stream. Reproducing some bugs may require referencing particular commits or paths, which becomes challenging after refnames and paths have been anonymized. You can ask for a particular token to be left as-is or mapped to a new value. For example, if you have a bug which reproduces with `git rev-list sensitive -- secret.c`, you can run: --------------------------------------------------- $ git fast-export --anonymize --all \ --anonymize-map=sensitive:foo \ --anonymize-map=secret.c:bar.c \ >stream --------------------------------------------------- After importing the stream, you can then run `git rev-list foo -- bar.c` in the anonymized repository. Note that paths and refnames are split into tokens at slash boundaries. The command above would anonymize `subdir/secret.c` as something like `path123/bar.c`; you could then search for `bar.c` in the anonymized repository to determine the final pathname. To make referencing the final pathname simpler, you can map each path component; so if you also anonymize `subdir` to `publicdir`, then the final pathname would be `publicdir/bar.c`. LIMITATIONS ----------- Since 'git fast-import' cannot tag trees, you will not be able to export the linux.git repository completely, as it contains a tag referencing a tree instead of a commit. SEE ALSO -------- linkgit:git-fast-import[1] GIT --- Part of the linkgit:git[1] suite

The git fast-export command with the --anonymize option allows users to export an anonymized repository, replacing sensitive information, while retaining the original tree and history patterns, making it useful for sharing bug reports with git developers, and also provides options for customizing the anonymization process and mapping specific tokens to new values.