Clarify rationale for ‘debian/rules’ shebang line (was: debian/rules "make -f" restriction)

[Ben Finney <ben+debian@benfinney.id.au>]

Manoj Srivastava <srivasta@debian.org> writes:

>         I think it would be a good idea to _add_ to policy a rule that
>  says that  "make -f debian/rules" and "./debian/rules" must behave
>  identically, to prevent confusion, and to promote reproducibility, and
>   conform to the principle of least surprise.

Rather than a new rule, I submit this patch to clarify the existing rule
for the shebang line.

=== modified file 'policy.sgml'
--- policy.sgml 2009-10-21 20:49:37 +0000
+++ policy.sgml 2009-10-31 00:59:18 +0000
@@ -1725,7 +1725,10 @@
        <p>
          It must start with the line <tt>#!/usr/bin/make -f</tt>,
          so that it can be invoked by saying its name rather than
-         invoking <prgn>make</prgn> explicitly.
+         invoking <prgn>make</prgn> explicitly. That is, invoking
+         either of <tt>make -f debian/rules <em>args...</em></tt>
+         or <tt>./debian/rules <em>args...</em></tt> should cause
+         identical behaviour in each case.
        </p>
 
        <p>

-- 
 \     “Listen: we are here on Earth to fart around. Don't let anybody |
  `\                  tell you otherwise.” —_Timequake_, Kurt Vonnegut |
_o__)                                                                  |
Ben Finney