Bug#397939: clean rule behavior underspecified and inconsistent with common practice

[Jonathan Nieder <jrnieder@gmail.com>]

Hi,

In 2006, Martin Zobel-Helas wrote:

> during the last months i had to review several packages. Quite a number
> of packages were not buildable two times (eg. "unrepresentable changes
> to source"). Most of these packages used svn-buildpackage or
> cvs-buildpackage. This bug is quite annoying as one needs to either
> manual interact or run dpkg-source -x again.

Of course policy forbids that.  The requirements in policy for
"debian/rules clean" are very stringent --- to avoid the
"unrepresentable changes" it would be enough to _remove_ the modified
(regenerated) files, but policy requires undoing everything the build
target did, or in other words restoring the original files.

In 2008, Henrique de Moraes Holschuh wrote:
> On Mon, 11 Feb 2008, Kapil Hari Paranjape wrote:

>> Note that if the upstream's auto-generated files are deleted during
>> the clean target, then the source *must* be re-packaged to avoid
>> needless clutter in the .diff.gz which is of a "negative" nature.
>
> Not so.  Deletions are ignored.  Ever tried it?

I rely on this when working with packages that use autotools, even
though it is against policy.

Would it make sense to add this exception (removal of files present in
the upstream tarball in the clean target to be ok as long as it
doesn't affect the build) to policy?  Would that be close enough to
the purpose of this bug to discuss here or should it be filed as a
separate proposal?

Thanks,
Jonathan