revsymbol not found

[aditya-shah73]

I keep getting this issue:

Traceback (most recent call last):
File "/Users/adshah/Desktop/fast-export/hg-fast-export.py", line 7, in
from mercurial.scmutil import revsymbol
ImportError: cannot import name revsymbol
/Applications/Xcode.app/Contents/Developer/usr/libexec/git-core/git-fast-import statistics:

[ghost]

Same error on Ubuntu Xenial.

[frej]

[This is a canned reply to issues that contain too little information for effective troubleshooting]

Please have a look at this blog post about writing effective bug reports. For fast-export you should at least:

• Check that you are using the latest released hg-fast-export.

• Check that your installed versions of Python and Mercurial meet the minimum requirements as specified in the README.

• Explain what you are trying to do, how you are doing it and in what environment.

• If your source repository is publicly available, give the URL.

• If hg-fast-export gives an error message and a backtrace, include that in the issue.

[chris-morgan]

v180610 broke support for Mercurial < 4.6 due to e200cec, which is going to affect almost everyone in practice because almost no one has Mercurial 4.6 already.

You have three primary options to work around this:

• Install mercurial 4.6 via pip (if you don’t know what you’re doing with pip, I recommend against this, because global installs are a mess);
• Downgrade fast-export to v180317;
• Include my patch at Restore support for mercurial<4.6 #133.

[Orabig]

I do confirm that downgrading fast-export works well. Installing additional packages when trying to migrate an old mercurial repository is generally not a good option, given that fast-export will be used in a one-shot process.

So my procedure becomes :

~$ git clone https://github.com/frej/fast-export.git
~$ cd fast-export
~$ git checkout tags/v180317
~$ cd ..
~$ mkdir new_git_repo
~$ cd new_git_repo
~$ git init
~$ ../fast-export/hg-fast-export.sh -r /old_hg_repo/

[chris-morgan]

Why close this? It’s still a serious issue, affecting almost everyone on Linux that uses Mercurial.

[camuso]

OK, I downgraded to version v180317, and the problem is gone.

chris-morgan is correct. This bug needs to be fixed.

[nobody93]

I've just made a clone from master branch as of today 17 July 2018, I still have following error, is it fixed in master branch or should I go to some branch?

fast-export/hg-fast-export.py", line 7, in
from mercurial.scmutil import revsymbol
ImportError: cannot import name revsymbol

[Orabig]

It is not fixed yet in the master branch.
As I said above, you should checkout tags/v180317 to have a working version.

[slxiao]

Checking out to tags/v180317 works but when command ../fast-export/hg-fast-export.sh is finished, the files in current directory are all deleted, and I have to run git stash to recover the files.

[eirnym]

@slxiao it's better to fill new issue to really track it.

[uthadehikaru]

@slxiao you have to run "git checkout HEAD" and voila, the file comes out

[ooxi]

Can this be fixed in master? Otherwise using the git manual's suggested approach is broken on the current Ubuntu LTS (18.04).

@chris-morgan's workaround worked btw.

[alexanpe]

I encountered this problem today. For it not to have been resolved in master in 18 months does seem a little odd.

[frej]

@alexanpe: See this comment in PR #132 for why there is no support for old Mercurial revisions.

[ooxi]

@frej So first upgrading the mercurial repository and then executing fast-export should work? How about probing the repository version first and then hinting a need to upgrade to the user?

[zerkms]

For those who are as me stuck with not being able to upgrade mercurial - I created a docker image https://hub.docker.com/r/zerkms/hg-fast-export

[pqr]

For those who are as me stuck with not being able to upgrade mercurial - I created a docker image https://hub.docker.com/r/zerkms/hg-fast-export

Great image, thank you!

But when I first run your container I got an error:

Status: Downloaded newer image for zerkms/hg-fast-export:latest
Error: The option core.ignoreCase is set to true in the git
repository. This will produce empty changesets for renames that just
change the case of the file name.
Use --force to skip this check or change the option with
git config core.ignoreCase false

So I created a Dockerfile with "--force" option:

FROM zerkms/hg-fast-export:latest
ENTRYPOINT ["/app/hg-fast-export.sh", "-r", "/hg", "--force"]

My be it's a good idea to add "--froce" to your docker image too?

[zerkms]

@pqr from the source code it looks like force disables some other checks as well. You could just add --force when you docker run the container.

[nogu3ira]

To fix:

sudo apt-get update
sudo apt-get install python-pip
pip install --upgrade Mercurial