build system: Remove make 3.81 "component_project_vars.mk: No such file or directory...

Also add an explicit make version check & warning.

diff --git a/make/project.mk b/make/project.mk
index a273da1c25c75012c588c315ca298fa144314363..a10f6cd24ae11abab1d51a39e9957ae262e0e917 100644 (file)
--- a/make/project.mk
+++ b/make/project.mk
@@ -36,6 +36,13 @@ help:
        @echo "See also 'make bootloader', 'make bootloader-flash', 'make bootloader-clean', "
        @echo "'make partition_table', etc, etc."
 
+# dependency checks
+ifndef MAKE_RESTARTS
+ifeq ("$(filter 4.% 3.81 3.82,$(MAKE_VERSION))","")
+$(warning "esp-idf build system only supports GNU Make versions 3.81 or newer. You may see unexpected results with other Makes.")
+endif
+endif
+
 # disable built-in make rules, makes debugging saner
 MAKEFLAGS_OLD := $(MAKEFLAGS)
 MAKEFLAGS +=-rR
@@ -105,7 +112,8 @@ COMPONENT_LDFLAGS :=
 # See the component_project_vars.mk target in component_wrapper.mk
 COMPONENT_PROJECT_VARS := $(addsuffix /component_project_vars.mk,$(notdir $(COMPONENT_PATHS_BUILDABLE)))
 COMPONENT_PROJECT_VARS := $(addprefix $(BUILD_DIR_BASE)/,$(COMPONENT_PROJECT_VARS))
-include $(COMPONENT_PROJECT_VARS)
+# this line is -include instead of include to prevent a spurious error message on make 3.81
+-include $(COMPONENT_PROJECT_VARS)
 
 # Also add top-level project include path, for top-level includes
 COMPONENT_INCLUDES += $(abspath $(BUILD_DIR_BASE)/include/)