add comment about for unbootstrapping hscolour; add test-rebuild script for testing changes

so far script gives diffs of requires and provides

ghc-rpm-macros.spec

@@ -4,6 +4,8 @@
 
 # uncomment to bootstrap without hscolour
 #%%global without_hscolour 1
+# uncomment to unbootstrap hscolour on again
+#%%undefine without_hscolour
 
 Name:           ghc-rpm-macros
 Version:        0.97.1

test-rebuild

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+PKG=$1
+
+fedpkg clone -a $PKG
+cd $PKG
+
+sudo yum build-depends $PKG
+
+fedpkg local
+
+mkdir -p test
+
+cd $(arch)
+
+PKGS=$(rpm -qp --qf "%{name}\n" *)
+
+sudo yum install $PKGS
+
+for i in $PKGS; do
+  for k in requires provides; do
+    rpm -qp --$k $i*.rpm > ../test/$i.$k.test
+    rpm -q --$k $i > ../test/$i.$k.installed
+    diff -u ../test/$i.$k.installed ../test/$i.$k.test > ../$i.$k.diff
+  done
+done