Bug#845715: debian-policy: Please document that packages are not allowed to write outside their source directories

[Johannes Schauer <josch@debian.org>]

Package: debian-policy
Severity: wishlist
Tags: patch

Hi,

source packages are forced to not write into $HOME by sbuild and
pbuilder, so any package attempting to do so currently FTBFS. It would
be nice to have this requirement be documented in policy. I propose the
following patch:


diff --git a/policy.sgml b/policy.sgml
index 9cd182b..42efd18 100644
--- a/policy.sgml
+++ b/policy.sgml
@@ -1944,6 +1944,16 @@ zope.
           For packages in the main archive, no required targets
           may attempt network access.
        </p>
+       <p>
+         None of the required targets must attempt to write outside of the
+         source package package directory tree. An exception to this rule is
+         the use of <file>/tmp</file> which is permitted as long as temporary
+         files are deleted and not re-used by subsequent execution of the
+         target. This is to prevent that source package builds create and
+         depend on state from the outside and thus affect multiple independent
+         rebuilds. Most notably, none of the required targets must attempt to
+         write into <file>$HOME</file>.
+       </p>
 
        <p>
          The targets are as follows:


Thoughts?

Thanks!

cheers, josch