[maemo-developers] [maemo-developers] Maemo 2.0/2.1 packages working on 3.0? Maybe not

[From: Aaron Levinson]

Detlef Schmicker and I released a new VNC viewer package on Friday, and as
preliminary tests using the previous 0.4.1 package by N800 users indicated
that it worked on the N800, I also uploaded the same package to the bora
garage repository and instructed users to use the auto-generated .install
file to install the package and associated repository on the N800.  Some
users had success installing 0.5 with this technique, but other users ran
up against a dependency issue with the libxau0 package.

I had some time to look into this issue today, and it appears that libxau0
is automatically added to the package dependency list by the maemo 2.0
build process (due to the standard "Depends: ${shlibs:Depends}" line in
the control file).  In addition, the libxau0 package is provided as part
of maemo 2.0 and 2.1 but is no longer included in maemo 3.0, presumably
because it is no longer necessary (at least, it isn't included in the 3.0
SDK, which I assume also reflects the state of the N800).  Some
knowledgeable users have worked around this problem by also adding some
mistral repositories to their repositories list, which causes libxau0 to
be downloaded, but realistically, this shouldn't be necessary.  Plus, I
doubt libxau0 is actually needed to run the application on maemo 3.0.

I'm not sure how common it is for libxau0 to be added to the dependency
list for packages built with the maemo 2.0 SDK, but if it is common, I
don't think it is correct to claim that maemo 2.0 or 2.1 packages will
work on maemo 3.0 without being rebuilt using the 3.0 SDK.  In order to
use such packages, users have to do some fudging to get legacy 2.0/2.1
packages installed on their 3.0 device.

At http://www.maemo.org//downloads/maemo_3_compatibility.html , it states
the following:  "Installation packages created for Nokia 770 will by
default work also with Nokia N800."  This unfortunately doesn't appear to
be the case.

As with packages built using the 2.1 SDK not working on maemo 2.0
installations, the auto-generated dependency issue strikes again, and it
effectively requires developers to download, install, and use the 3.0 SDK 
to build packages that will work "out-of-the-box" on the N800.

Aaron