$NetBSD$

# Respect build environment

--- Makefile.orig	2020-07-21 09:19:56.000000000 +0000
+++ Makefile
@@ -22,25 +22,26 @@
 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 # DEALINGS IN THE SOFTWARE.
 
-CC     = gcc
-AR     = ar
-RANLIB = ranlib
+CC     ?= gcc
+AR     ?= ar
+RANLIB ?= ranlib
 
 # Default libraries to link if configure is not used
 htslib_default_libs = -lz -lm -lbz2 -llzma -lcurl
 
-CPPFLAGS =
+# CPPFLAGS =
 # TODO: make the 64-bit support for VCF optional via configure, for now add -DVCF_ALLOW_INT64
 #       to CFLAGS manually, here or in config.mk if the latter exists.
 # TODO: probably update cram code to make it compile cleanly with -Wc++-compat
 # For testing strict C99 support add -std=c99 -D_XOPEN_SOURCE=600
 #CFLAGS   = -g -Wall -O2 -pedantic -std=c99 -D_XOPEN_SOURCE=600
-CFLAGS   = -g -Wall -O2 -fvisibility=hidden
+CFLAGS   ?= -g -Wall -O2 -fvisibility=hidden
 EXTRA_CFLAGS_PIC = -fpic
-LDFLAGS  = -fvisibility=hidden
+LDFLAGS  ?= -fvisibility=hidden
 LIBS     = $(htslib_default_libs)
 
-prefix      = /usr/local
+PREFIX      ?= /usr/local
+prefix      = $(PREFIX)
 exec_prefix = $(prefix)
 bindir      = $(exec_prefix)/bin
 includedir  = $(prefix)/include
@@ -69,7 +70,7 @@ BUILT_PROGRAMS = \
 	htsfile \
 	tabix
 
-BUILT_TEST_PROGRAMS = \
+BUILT_TEST_PROGRAMS ?= \
 	test/hts_endian \
 	test/fieldarith \
 	test/hfile \
@@ -90,7 +91,7 @@ BUILT_TEST_PROGRAMS = \
 	test/test-bcf-translate \
 	test/test-parse-reg
 
-BUILT_THRASH_PROGRAMS = \
+BUILT_THRASH_PROGRAMS ?= \
 	test/thrash_threads1 \
 	test/thrash_threads2 \
 	test/thrash_threads3 \
