It seems we also need to pass DOCKER_BUILDKIT as an argument to docker itself to get the full benefit of caching. Signed-off-by: Alex Bennée <alex.bennee@xxxxxxxxxx> Suggested-by: Fabiano Rosas <farosas@xxxxxxx> --- tests/docker/Makefile.include | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tests/docker/Makefile.include b/tests/docker/Makefile.include index 54ed77f671..9401525325 100644 --- a/tests/docker/Makefile.include +++ b/tests/docker/Makefile.include @@ -39,7 +39,7 @@ docker-qemu-src: $(DOCKER_SRC_COPY) # General rule for building docker images. docker-image-%: $(DOCKER_FILES_DIR)/%.docker $(call quiet-command, \ - $(RUNC) build \ + DOCKER_BUILDKIT=1 $(RUNC) build \ $(if $V,,--quiet) \ $(if $(NOCACHE),--no-cache, \ $(if $(DOCKER_REGISTRY),--cache-from $(DOCKER_REGISTRY)/qemu/$*)) \ -- 2.39.2
