--- GNUmakefile.orig	2021-04-24 10:47:51 UTC
+++ GNUmakefile
@@ -4,10 +4,10 @@
 # in /opt/diet, where they are in the default search path for my diet libc
 # work but don't conflict with anything there.  YMMV.
 
-prefix=/opt/diet
+prefix=${PREFIX}
 LIBDIR=${prefix}/lib
 INCLUDEDIR=${prefix}/include
-MAN3DIR=${prefix}/man/man3
+MAN3DIR=${prefix}/share/man/man3
 
 LIBS=byte.a fmt.a scan.a str.a uint.a open.a stralloc.a unix.a socket.a \
 buffer.a mmap.a taia.a tai.a dns.a case.a mult.a array.a io.a \
@@ -39,10 +39,10 @@ NATIVE=
 OPT_REG=-O2
 OPT_PLUS=-O3 $(NATIVE)
 
-DEFINE=-D_REENTRANT
+DEFINE=-D_REENTRANT -fPIC
 
-CFLAGS=-pipe $(WARN) $(DEFINE) $(OPT_REG)
-CFLAGS_OPT=-pipe $(WARN) $(DEFINE) $(OPT_PLUS)
+CFLAGS+=-pipe $(WARN) $(DEFINE)
+CFLAGS_OPT=$(CFLAGS)
 
 #CFLAGS=-pipe -Os -march=pentiumpro -mcpu=pentiumpro -fomit-frame-pointer -fschedule-insns2 -Wall