diff -ur dpkg-1.15.5.6.orig/scripts/Dpkg/Arch.pm dpkg-1.15.5.6/scripts/Dpkg/Arch.pm
--- dpkg-1.15.5.6.orig/scripts/Dpkg/Arch.pm	2010-01-08 08:00:34.000000000 +0000
+++ dpkg-1.15.5.6/scripts/Dpkg/Arch.pm	2010-10-17 12:29:46.916000478 +0100
@@ -47,8 +47,9 @@
 	return $build_arch if defined $build_arch;
 
 	my $build_arch = `dpkg --print-architecture`;
-	# FIXME: Handle bootstrapping
-	syserr("dpkg --print-architecture failed") if $? >> 8;
+    if ($? >> 8 || $build_arch =~ /^\s*$/) {
+        $build_arch = get_raw_host_arch();
+    }
 
 	chomp $build_arch;
 	return $build_arch;