Chunk 1:	Change PREFIX variables
Chunk 2:	Append local CPPFLAGS
diff -ura tscrape.old/Makefile tscrape.new/Makefile
--- tscrape.old/Makefile	2020-03-30 21:06:13.524958558 +1100
+++ tscrape.new/Makefile	2020-03-30 21:07:54.628158194 +1100
@@ -4,16 +4,16 @@
 VERSION = 0.4
 
 # paths
-PREFIX = /usr/local
-MANPREFIX = ${PREFIX}/man
-DOCPREFIX = ${PREFIX}/share/doc/tscrape
+PREFIX = /usr
+MANPREFIX = ${PREFIX}/share/man
+DOCPREFIX = ${PREFIX}/share/doc/tscrape-git
 
 RANLIB = ranlib
 
 # use system flags.
 TSCRAPE_CFLAGS = ${CFLAGS}
 TSCRAPE_LDFLAGS = ${LDFLAGS}
-TSCRAPE_CPPFLAGS = -D_DEFAULT_SOURCE
+TSCRAPE_CPPFLAGS = ${CPPFLAGS} -D_DEFAULT_SOURCE
 
 BIN = \
 	tscrape\