aports

 1Make sure common environment variables (CC, CFLAGS, LDFLAGS, …) are not
 2overwritten. Also allow configuring the X11 library and include
 3directory separately.
 4
 5diff -upr drawterm-0_git20240320.orig/Make.unix drawterm-0_git20240320/Make.unix
 6--- drawterm-0_git20240320.orig/Make.unix	2024-03-20 18:10:01.746844469 +0100
 7+++ drawterm-0_git20240320/Make.unix	2024-03-20 18:11:00.280317013 +0100
 8@@ -5,13 +5,14 @@ AR=ar
 9 AS=as
10 RANLIB=ranlib
11 X11=/usr/X11R6
12-CC=gcc
13-CFLAGS=-Wall -Wno-missing-braces -Wno-parentheses -ggdb -I$(ROOT) -I$(ROOT)/include -I$(ROOT)/kern -c -I$(X11)/include -D_THREAD_SAFE $(PTHREAD) -O2
14+CC?=gcc
15+CFLAGS?=-O2
16+CFLAGS+=-Wall -Wno-missing-braces -Wno-parentheses -ggdb -I$(ROOT) -I$(ROOT)/include -I$(ROOT)/kern -c -I$(X11)/include -D_THREAD_SAFE $(PTHREAD)
17 O=o
18 OS=posix
19 GUI=x11
20 LDADD=-L$(X11)/lib64 -L$(X11)/lib -lX11 -ggdb -lm
21-LDFLAGS=$(PTHREAD)
22+LDFLAGS+=$(PTHREAD)
23 TARG=drawterm
24 # AUDIO=none
25 AUDIO=unix