Makefiles are patched with debian/*.patch files, not by the build system
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -53,8 +53,8 @@
     dist => { COMPRESS=>"gzip", SUFFIX=>"gz" },
 );
 
-editTexMakefile();      # edit Makefile in tex subdirectory
-editMakefile();         # make changes to Makefile just built by WriteMakefile()
+#editTexMakefile();      # edit Makefile in tex subdirectory
+#editMakefile();         # make changes to Makefile just built by WriteMakefile()
 
 
 #########################################################
@@ -72,6 +72,13 @@
 fonts :
 	cd tex; \${MAKE} fonts
 
+.tex.dvi :
+	env TEXINPUTS=.:tex: TFMFONTS=.:tex: tex \$<
+
+.SUFFIXES : .tex .dvi
+
+install :: install_tex manual.dvi
+
 TEX_TARGET
 }