[moin-user] moin to dokuwiki export does not work, namespace error

[Paul Boddie]

On Friday, 9 December 2022 16:22:33 CET Rudolf Reuter wrote:
> Hello,
> I have tried to convert my MoinMoin wiki v.1.9.9 to dokuwiki.
> There is a converter program available, but it does not work.
> Reference: https://github.com/glensc/moin2doku
> Unfortunately the author no longer want to give support.

This program is designed for Moin 1.5, so there may be compatibility issues 
with various APIs. The Moin wiki syntax changed in Moin 1.6, if I remember 
correctly, but if this converter uses the Moin parser API and if the dokuwiki 
formatter is still usable for today's DocuWiki, then maybe it will produce 
good enough results.

Amusingly, the DocuWiki page for that converter makes vague remarks about Moin 
being "not as stable as it looks like" and links to a German language page 
related to Ubuntu. Moin has been pretty stable since Moin 1.6 came out, I 
would say.

One more general remark I would make is to consider the availability of tools 
to migrate from DocuWiki rather than to it. If that scenario isn't great, you 
may be saving up some pain in the future.

> In order to **make testing easier** I replaced in file moin2doku.py
> line 243
>     opts, args = getopt.getopt(sys.argv[1:], 'hfad:p:r:i:I:', [ "help" ])
> with
>     sys.argv[1:] = "-F wiki/data/pages/FrontPage"  # RR "single page"
> parameter sys.argv[2:] = "-d out"
>  
> Unfortunately there is a **namespace problem**.
>  
> What I did to make it run:
> Copy the moin2doku files into the moinmoin installation.

I guess you have a directory containing the usual Moin distribution, with the 
MoinMoin directory being the package that gets imported. If you put the 
moin2doku files in that Moin distribution directory then I think it ought to 
work. This should mean that when you run moin2doku.py it will find the 
MoinMoin package and the different modules.

If, on the other hand, the MoinMoin directory lives in somewhere like site-
packages or dist-packages then I wouldn't copy the moin2doku files into the 
same location. Instead, just rely on the PYTHONPATH/sys.path to help find the 
MoinMoin package.

> I set all files to owner www-data:www-data

You only need to do this to publish the output of the conversion. Setting the 
owner of these programs shouldn't be necessary, although you will need to make 
sure that if you are running them as your own user, the permissions on the 
files and on the Moin sources permit your user's access.

> Start moin2doku.py:
> **$ sudo python2 moin2doku.py**

And so it shouldn't be necessary to run this with superuser privileges.

> --- changes in moin2doku.py, use tabs only !
>  
> When you start moim2doku.py , you get an error in file MoinMoin/user.py line
> 27 import md5crypt
>  
> **ImportError**: no module named md5crypt
> Path: MoinMoin/support/md5crypt.py
>  
> When you change line 27 from:
>     import md5crypt
> to:
>     import support.md5crypt
> 
> This error is gone, but then comes the next namespace error.

This does look a bit strange.

> But the next import fails, and I did not found a solution.
>     user.py line 38
> MoinMoin/util/filesystem.py
>     module line 33: support.werkzeug.posixemulationn # support added
>     ./MoinMoin/support/werkzeug/posixemulation.py
>  
> I am still searching how to **fix the namespace error**.

Here, it would be useful to see the actual error message - the traceback - so 
that we can better understand it and avoid misunderstandings. For example, it 
is actually MoinMoin/util/filesys.py where the error arises.

> It would be very nice if someone with more knowledge could help me please.

For now, we may ignore the md5crypt error which may only manifest itself 
because we are importing MoinMoin.user directly, and because who knows what 
kind of weird module namespace stuff might be done when Moin is launched 
normally to prevent it from happening? Again, I find the presence of the error 
very odd, but then I'm not doing something like this myself very often any 
more.

However, I would guess that the Werkzeug error may have something to do with 
either a missing package for Werkzeug, the wrong version being installed, or a 
problem finding it when run as superuser, which you probably shouldn't be 
doing. Diagnosis involving sys.path could be helpful here.

I hope this is useful.

Paul