Build (backport) an newer Ubuntu package to run on an older Ubuntu version

[fuoco]

I made symlinks from /var/cache/prevu{builds,src} to my home directory on another partition, so that I have more space when building.stuff (my root partition is too restrained).
That works great really. The only issue is that it won't save the downloaded dependencies where it can later on reuse them for another build or a rebuild. So everytime I build something it downloads the entire list of dependencies from scratch. Is there some way around it? is this a bug?
I get lots of warnings like:

-> new cache content libwww-perl_5.805-1_all.deb added
ln: creating hard link `/var/cache/pbuilder/aptcache//libwww-perl_5.805-1_all.deb' to `/home/gad/prevu/build-tmp/29010/var/cache/apt/archives/libwww-perl_5.805-1_all.deb': Invalid cross-device link

etc..

[jdong]

You should also change /var/cache/pbuilder/aptcache/ to a symlink to somewhere onthe same device as your prevu builders.

[fuoco]

You should also change /var/cache/pbuilder/aptcache/ to a symlink to somewhere onthe same device as your prevu builders.

thanks, that helps!

[hfdragon]

I just installed prevu, run prevu-init, and tried to backport some apps.

Each time I get this (or a similar) error :

cp: cannot create regular file `/var/cache/pbuilder/result/tomboy_0.7.4-0ubuntu1~7.04prevu1.dsc': Permission denied

Should I run prevu with sudo ?

[jdong]

No, you should run sudo prevu-update to reset permissions.

[hfdragon]

No, you should run sudo prevu-update to reset permissions.

I don't know why, but it's not working..

I still get this kind of error :

cp: cannot create regular file `/var/cache/pbuilder/result/backuppc_3.0.0-3ubuntu1~7.04prevu1.dsc': Permission denied

[jdong]

Hmm, it's trying to save the results to the wrong place. What version of prevu is this, and where was it downloaded from? Have you previously done any setup work with pbuilder?

[hfdragon]

Version is 1:0.4.1bzr46-0ubuntu2 (feisty)

And I got ,it from universe (archive.ubuntu.com/universe)

Edit : I tested prevu on another machine with feisty installed and it worked all right... so I think maybe one of the dependencies isn't OK, I'l need some time to check that..

[hfdragon]

Ok, I found which packacge was 'faulty'.

I got pbuilder version form telemail.fi (which I added to my sources.list to get thunderbird 2.0) with a version number : 0.169ubuntu1~feisty0.1

Changed it back to the 0.161ubuntu2 (from the ubuntu repos) and now prevu is working correctly

[jdong]

ah, ok, good. What happened was that your other pbuilder wasn't respecting the option to set the results directory. Prevu forces the results to be placed in /var/cache/prevu/DISTRO-debs where DISTRO is your Ubuntu version. However, your pbuilder was ignoring this directive and trying to shove it in /var/cache/pbuilder/results, which indeed the regular user cannot write to.