Problem with --instdir and pre/postinst scripts

[Bjoern Stierand <bjoern@skyrix.com>]

Hi List,

I'm currently building some packages and I encountered a
strange problem that I couldn't solve yet.

What I want to do is to install the built packages into an
alternative directory using the --instdir switch of dpkg.
But when I try to install the package, the following
happens:

-- snip --
root@grobi:build> dpkg --instdir=/home/foo/ -i mypackage.deb 
Selecting previously deselected package mypackage.
(Reading database ... 666 files and directories currently installed.)
Unpacking mypackage (from mypackage.deb)
...
dpkg (subprocess): unable to execute new pre-installation script: No such file or directory
dpkg: error processing mypackage.deb (--install):
 subprocess pre-installation script returned error exit
 status 2
 Errors were encountered while processing:
  mypackage.deb
-- snap --

This only happens when using --instdir, the files are
installed, but the pre/postinst scripts are obviously not
executed. Using just 'dpkg -i' installs the package without any problems 
(and executes the preinst and postinst scripts flawlessly).

Has anyone an idea how to solve this one? I read in the dpkg
manpage that it uses chroot when installing the package,
could this problem be related to the chroot thing (maybe it
doesn't find a shell then or something like that).

Thanks in advance for your help.

Bjoern

-- 
Bjoern Stierand                              mail:  mailto:bs@skyrix.com
    SKYRIX Software AG, 39104 Magdeburg, Germany - www.skyrix.com