[Sugar-devel] Bundling libraries, RPMs? (was Re: WatchMe-1, a VNC activity)

[Peter Robinson]

>>>> Indeed.  The #1 thing to do, IMHO, is to get rid of the "yum install"
>>>> requirement.  In the short term, the only way to do that is to bundle
>>>> gtk-vnc and gtk-vnc-python into the .xo, which is fine... I'm just not
>>>> quite sure how to do it.
>>> If someone does know how to do this sort of thing, a quick how-to
>>> writeup would be immensely useful!
>>
>> Please DON'T do this. There is absolutely NO guarantee that this will
>> work between Fedora versions, it fact its known to break, just look at
>> a recent rawhide report and see the breakage for pippy. Its a complete
>> hack and a complete mess and it will guarantee that things will break
>> and the activity will then only be supported on the sugar release that
>> it was based upon rather than be supportable across multiple sugar
>> releases because the underlying Fedora libraries that the included
>> binaries link against will have changed. If you have something that
>> has a dependency you'd be much better to package it up as an rpm where
>> you can do proper rpm requires which means it can pull in any required
>> dependencies. I will quite happily assist in rpm creation and support.
>
> So, in fact, I have taken a middle way that is somewhat interesting.  In
> WatchMe-2 (currently pending in activities.sugarlabs.org; I'm not sure why
> it hasn't been accepted) I have bundled the gtk-vnc and gtk-vnc-python
> packages from Fedora 9, as well as a static binary of x11vnc (which still
> has not been accepted into the Fedora repositories).  This makes the
> bundle work "out of the box" on OLPC's XO distros.
>
> To make this work, I've had to modify PATH, LD_LIBRARY_PATH, and
> PYTHONPATH.  Normally, this setup would be unreliable on other versions of
> Fedora or another distribution, and absolutely broken on another
> architecture (e.g. PowerPC).  However, rather than naively setting these
> PATH variables, I have introduced a compatibility shim that inspects the
> current PATH, determines the current Python library search path, and
> parses /etc/ld.so.conf to work out the systemwide libraries path.  It then
> generates these variables so as to ensure that the bundles libraries are
> inserted with _lowest_ priority, rather than _highest_ priority as is
> typically the case.
>
> As a result, if you install gtk-vnc, gtk-vnc-python, and x11vnc, WatchMe-2
> should work on any distribution, on any architecture.  Additionally, it
> runs on OLPC's Fedora 9 without any root privileges required.
>
> I had planned on describing this system after WatchMe-2 appeared on ASLO,
> but I guess our sysadmins have been a bit too busy fighting fires to
> approve new Activities.

Congratulations! That's a truly ugly hack. Oh and BTW it won't work on
any architecture (like PPC and probably not x86_64 too) , and will
likely break in other ways, its successfully done that for pippy in
rawhide!

Peter