diff -u -r criu-3.16.1/compel/test/fdspy/Makefile criu-3.16.1/compel/test/fdspy/Makefile
--- criu-3.16.1/compel/test/fdspy/Makefile	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/compel/test/fdspy/Makefile	2023-07-14 12:04:56.000000000 +0800
@@ -1,4 +1,4 @@
-CC	:= gcc
+CC	?= gcc
 CFLAGS	?= -O2 -g -Wall -Werror
 
 COMPEL		:= ../../../compel/compel-host
diff -u -r criu-3.16.1/compel/test/infect/Makefile criu-3.16.1/compel/test/infect/Makefile
--- criu-3.16.1/compel/test/infect/Makefile	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/compel/test/infect/Makefile	2023-07-14 12:05:03.000000000 +0800
@@ -1,4 +1,4 @@
-CC	:= gcc
+CC	?= gcc
 CFLAGS	?= -O2 -g -Wall -Werror
 
 COMPEL		:= ../../../compel/compel-host
diff -u -r criu-3.16.1/compel/test/rsys/Makefile criu-3.16.1/compel/test/rsys/Makefile
--- criu-3.16.1/compel/test/rsys/Makefile	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/compel/test/rsys/Makefile	2023-07-14 12:04:49.000000000 +0800
@@ -1,4 +1,4 @@
-CC	:= gcc
+CC	?= gcc
 CFLAGS	?= -O2 -g -Wall -Werror
 
 COMPEL		:= ../../../compel/compel-host
diff -u -r criu-3.16.1/scripts/ci/docker.env criu-3.16.1/scripts/ci/docker.env
--- criu-3.16.1/scripts/ci/docker.env	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/scripts/ci/docker.env	2023-07-14 11:51:52.000000000 +0800
@@ -1,4 +1,4 @@
 SKIP_CI_PREP=1
 ZDTM_OPTS=-x zdtm/static/binfmt_misc -x zdtm/static/sched_policy00
-CC=gcc
+CC=$(CC)
 SKIP_EXT_DEV_TEST=1
diff -u -r criu-3.16.1/scripts/ci/run-ci-tests.sh criu-3.16.1/scripts/ci/run-ci-tests.sh
--- criu-3.16.1/scripts/ci/run-ci-tests.sh	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/scripts/ci/run-ci-tests.sh	2023-07-14 12:06:23.000000000 +0800
@@ -36,7 +36,7 @@
 	# This can fail on aarch64 travis
 	service apport stop || :
 
-	if [ "$CLANG" = "1" ]; then
+	if [ "$CC" = "clang" ]; then
 		# clang support
 		CC=clang
 		# If this is running in an environment without gcc installed
diff -u -r criu-3.16.1/scripts/nmk/scripts/tools.mk criu-3.16.1/scripts/nmk/scripts/tools.mk
--- criu-3.16.1/scripts/nmk/scripts/tools.mk	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/scripts/nmk/scripts/tools.mk	2023-07-14 11:52:23.000000000 +0800
@@ -7,7 +7,7 @@
 ifeq ($(origin LD), default)
 LD		:= $(CROSS_COMPILE)$(HOSTLD)
 endif
-HOSTCC		?= gcc
+HOSTCC		?= $(CC)
 ifeq ($(origin CC), default)
 CC		:= $(CROSS_COMPILE)$(HOSTCC)
 endif
diff -u -r criu-3.16.1/test/others/app-emu/job/Makefile criu-3.16.1/test/others/app-emu/job/Makefile
--- criu-3.16.1/test/others/app-emu/job/Makefile	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/test/others/app-emu/job/Makefile	2023-07-14 12:01:22.000000000 +0800
@@ -2,10 +2,10 @@
 .PHONY: all
 
 %.o: %.c
-	gcc -c $< -o $@
+	$(CC) -c $< -o $@
 
 job: job.o
-	gcc -o $@ job.o
+	$(CC) -o $@ job.o
 
 clean:
 	rm -f *.o job
diff -u -r criu-3.16.1/test/others/app-emu/make/Makefile criu-3.16.1/test/others/app-emu/make/Makefile
--- criu-3.16.1/test/others/app-emu/make/Makefile	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/test/others/app-emu/make/Makefile	2023-07-14 12:03:31.000000000 +0800
@@ -3,7 +3,7 @@
 .PHONY: all
 
 %.o: %.c
-	gcc -c $< -o $@
+	$(CC) -c $< -o $@
 
 foo%.c: tmpl.c
 	cp $< $@
diff -u -r criu-3.16.1/test/others/ext-links/Makefile criu-3.16.1/test/others/ext-links/Makefile
--- criu-3.16.1/test/others/ext-links/Makefile	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/test/others/ext-links/Makefile	2023-07-14 12:03:28.000000000 +0800
@@ -1,4 +1,4 @@
 all: mvlink.so
 
 mvlink.so: mvlink.c
-	gcc -g -Werror -Wall -shared -nostartfiles mvlink.c -o mvlink.so -iquote ../../../criu/include -fPIC
+	$(CC) -g -Werror -Wall -shared -nostartfiles mvlink.c -o mvlink.so -iquote ../../../criu/include -fPIC
diff -u -r criu-3.16.1/test/others/libcriu/Makefile criu-3.16.1/test/others/libcriu/Makefile
--- criu-3.16.1/test/others/libcriu/Makefile	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/test/others/libcriu/Makefile	2023-07-14 12:03:37.000000000 +0800
@@ -16,13 +16,13 @@
 
 define genb
 $(1): $(1).o lib.o
-	gcc $$^ -L ../../../../criu/lib/c/ -L ../../../../criu/images/ -lcriu -o $$@
+	$(CC) $$^ -L ../../../../criu/lib/c/ -L ../../../../criu/images/ -lcriu -o $$@
 endef
 
 $(foreach t, $(TESTS), $(eval $(call genb, $(t))))
 
 %.o: %.c
-	gcc -c $^ -iquote ../../../../criu/criu/include -I../../../../criu/lib/c/ -I../../../../criu/images/ -o $@ -Werror
+	$(CC) -c $^ -iquote ../../../../criu/criu/include -I../../../../criu/lib/c/ -I../../../../criu/images/ -o $@ -Werror
 
 clean: libcriu_clean
 	rm -rf $(TESTS) $(TESTS:%=%.o) lib.o
diff -u -r criu-3.16.1/test/others/Makefile criu-3.16.1/test/others/Makefile
--- criu-3.16.1/test/others/Makefile	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/test/others/Makefile	2023-07-14 12:03:25.000000000 +0800
@@ -1,2 +1,2 @@
 loop:
-	gcc -Wall loop.c -o loop
+	$(CC) -Wall loop.c -o loop
diff -u -r criu-3.16.1/test/others/mounts/ext/Makefile criu-3.16.1/test/others/mounts/ext/Makefile
--- criu-3.16.1/test/others/mounts/ext/Makefile	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/test/others/mounts/ext/Makefile	2023-07-14 12:01:34.000000000 +0800
@@ -1,13 +1,13 @@
 all: ext-mount.so ns_init
 
 ext-mount.so: ext-mount.c
-	gcc -g -Werror -Wall -shared -nostartfiles ext-mount.c -o ext-mount.so -iquote ../../../include -fPIC
+	$(CC) -g -Werror -Wall -shared -nostartfiles ext-mount.c -o ext-mount.so -iquote ../../../include -fPIC
 
 ns_init: ns_init.o
-	gcc -static $< -o $@
+	$(CC) -static $< -o $@
 
 ns_init.o: ns_init.c
-	gcc -c $< -o $@
+	$(CC) -c $< -o $@
 
 run: all
 	./run.sh
diff -u -r criu-3.16.1/test/others/unix-callback/Makefile criu-3.16.1/test/others/unix-callback/Makefile
--- criu-3.16.1/test/others/unix-callback/Makefile	2021-10-14 13:44:30.000000000 +0800
+++ criu-3.16.1/test/others/unix-callback/Makefile	2023-07-14 12:01:53.000000000 +0800
@@ -7,16 +7,16 @@
 	protoc-c --proto_path=. --c_out=. unix.proto
 
 unix-lib.so: unix-lib.c unix.pb-c.c
-	gcc -g -Werror -Wall -shared -nostartfiles unix-lib.c unix.pb-c.c -o unix-lib.so -iquote ../../../criu/include -fPIC
+	$(CC) -g -Werror -Wall -shared -nostartfiles unix-lib.c unix.pb-c.c -o unix-lib.so -iquote ../../../criu/include -fPIC
 
 syslog-lib.so: syslog-lib.c
-	gcc -g -Werror -Wall -shared -nostartfiles syslog-lib.c -o syslog-lib.so -iquote ../../../criu/include -fPIC
+	$(CC) -g -Werror -Wall -shared -nostartfiles syslog-lib.c -o syslog-lib.so -iquote ../../../criu/include -fPIC
 
 unix-server: unix-server.c
-	gcc -Werror -Wall -o unix-server unix-server.c
+	$(CC) -Werror -Wall -o unix-server unix-server.c
 
 unix-client: unix-client.c
-	gcc -Werror -Wall -o unix-client unix-client.c
+	$(CC) -Werror -Wall -o unix-client unix-client.c
 
 clean:
 	rm -rf data unix-lib.so unix-server unix-client syslog-lib.so output pid unix.pb-c.*