build/rules_pear.mk contains a contruct in the install-modules target whereby no matter what happens, the rule will always succeed.  From an autobuilding and packaging perspective (as in the case of Debian, for instance), this is horribly broken, as it could lead to empty packages, with no one the wiser.

The reason for the "|| true" was so that the rule wouldn't bomb out if there were no modules to install, however it causes the exact opposite problem instead (if there is are supposed to be modules, but they don't get built correctly, we continue on anyway).

What follows is a patch to change the behaviour so that we still carry on gracefully if there's no "modules" directory, but if there is one, we will die horribly if installing from it fails:

--------
--- rules_pear.mk       Tue Mar 13 10:54:38 2001
+++ rules_pear.mk.new   Tue Mar 12 05:45:22 2002
@@ -62,11 +62,12 @@
        @rm -f $(SUBDIRS) 2>/dev/null || true
 
 install-modules:
-       @test -d modules && \
+       if [ -d modules ]; then \
        $(mkinstalldirs) $(moduledir) && \
        echo "installing shared modules into $(moduledir)" && \
        rm -f modules/*.la && \
-       cp modules/* $(moduledir) || true
+       cp modules/* $(moduledir); \
+       fi
 
 include $(builddir)/.deps
-----------

... Adam Conrad
(the new Debian php4 maintainer)