Bug#561756: lintian: [new check] Architecture dependent packages without architecture dependent files

[Russ Allbery <rra@debian.org>]

"Carl "Fürstenberg\"" <azatoth@gmail.com> writes:

> per policy 5.6.8 Architecture: all must be used if package doesn't
> contain arch depentent files. I dont know how common this error is
> (noticed the error in the iwatch package). I though that this might be
> useful for lintian to catch, so I've tried to write a simple check for
> this.

> I don't know how many false positives it will generate, as it mearly
> checks if "file -i" says if the mime major is not "text".

The hard part about this is that one frequently cannot tell from the file
type whether it's architecture-dependent.  A great example that frequently
arises are development headers that include type size information, which
varies by architecture.  Even the iwatch package actually is
architecture-dependent since it will only work on Linux, although in that
case its dependencies take care of that and it's probably safe to make it
arch: all.

Another case that has come up is a metapackage that needs to be
architecture-dependent since it has different dependencies on different
architectures.  The package itself won't contain any
architecture-dependent files.  I also have a package that contains only
source code but is architecture-dependent, since what it contains is the
necessary source for building a kernel module, and it's the stripped
source that contains only the bits needed for that architecture.

I agree it would be great to have something to check this, but I'm not
sure how to go about it without a lot of false positives.  Even Perl
scripts can be architecture-dependent if they use pack to read binary
data, although they normally aren't.

We may be able to do something experimental or with a very low certainty,
but it's going to be tricky.

-- 
Russ Allbery (rra@debian.org)               <http://www.eyrie.org/~eagle/>