Makefile: make_parallel_flags via env variable
/proc/cpuinfo with container builds may lead to jenkins failures
ability to pass in MAKE_PARALLEL_FLAGS via env directly for
container builds
@@ -645,7 +645,7 @@ configure_check_timestamp = \
# for file presence and content; for now this will have to do.
MAKE_PARALLEL_JOBS = -j $(if $(shell [ -f /proc/cpuinfo ] && head /proc/cpuinfo), \
$(shell grep -c ^processor /proc/cpuinfo), 2)
-MAKE_PARALLEL_FLAGS = $(if $($(PACKAGE)_make_parallel_fails),,$(MAKE_PARALLEL_JOBS))
+MAKE_PARALLEL_FLAGS ?= $(if $($(PACKAGE)_make_parallel_fails),,$(MAKE_PARALLEL_JOBS))
# Make command shorthand for packages & tools.
PACKAGE_MAKE = \
