Don't ignore makeinfo errors.
diff --git a/Doc/Makefile b/Doc/Makefile
index ad1a3cb..89d8237 100644
--- a/Doc/Makefile
+++ b/Doc/Makefile
@@ -224,7 +224,7 @@
 	mv temp.texi $@
 
 python-lib.info: lib.texi
-	-$(MAKEINFO) --footnote-style end --fill-column 72 \
+	$(MAKEINFO) --footnote-style end --fill-column 72 \
 		     --paragraph-indent 0 $<
 
 # this is needed to prevent a second set of info files from being generated,