build system: Explicitly disallow 'clean' along with non-cleaning targets

Too hard to stage the dependencies so that all clean steps complete before any build steps begin. Also, using and then
deleting and then regenerating SDKCONFIG_MAKEFILE in one pass is really hard to manage successfully.

make/project.mk

@@ -45,10 +45,18 @@ help:
 # dependency checks
 ifndef MAKE_RESTARTS
 ifeq ("$(filter 4.% 3.81 3.82,$(MAKE_VERSION))","")
-$(warning "esp-idf build system only supports GNU Make versions 3.81 or newer. You may see unexpected results with other Makes.")
+$(warning esp-idf build system only supports GNU Make versions 3.81 or newer. You may see unexpected results with other Makes.)
 endif
 endif
 
+# can't run 'clean' along with any non-clean targets
+ifneq ("$(filter clean% %clean,$(MAKECMDGOALS))" ,"")
+ifneq ("$(filter-out clean% %clean,$(MAKECMDGOALS))", "")
+$(error esp-idf build system doesn't support running 'clean' targets along with any others. Run 'make clean' and then run other targets separately.)
+endif
+endif
+
+
 # make IDF_PATH a "real" absolute path
 # * works around the case where a shell character is embedded in the environment variable value.
 # * changes Windows-style C:/blah/ paths to MSYS/Cygwin style /c/blah
@@ -404,10 +412,11 @@ size-files: $(APP_ELF)
 size-components: $(APP_ELF)
 	$(PYTHON) $(IDF_PATH)/tools/idf_size.py --archives $(APP_MAP)
 
-# NB: this ordering is deliberate (app-clean before config-clean),
-# so config remains valid during all component clean targets
-config-clean: app-clean $(call prereq_if_explicit,bootloader-clean)
-clean: config-clean
+# NB: this ordering is deliberate (app-clean & bootloader-clean before
+# _config-clean), so config remains valid during all component clean
+# targets
+config-clean: app-clean bootloader-clean
+clean: app-clean bootloader-clean config-clean
 
 # phony target to check if any git submodule listed in COMPONENT_SUBMODULES are missing
 # or out of date, and exit if so. Components can add paths to this variable.

tools/ci/build_examples.sh

@@ -116,9 +116,10 @@ build_example () {
         # build non-verbose first
         local BUILDLOG=${PWD}/examplebuild.${ID}.log
         (
-            make MAKEFLAGS= clean defconfig &> >(tee -a "${BUILDLOG}") &&
-            make all &> >(tee -a "${BUILDLOG}")
-        ) || {
+            make MAKEFLAGS= clean &&
+            make MAKEFLAGS= defconfig &&
+            make all
+        ) &> >(tee -a "${BUILDLOG}") || {
             RESULT=$?; FAILED_EXAMPLES+=" ${EXAMPLE_NAME}"
             make MAKEFLAGS= V=1 clean defconfig && make V=1 # verbose output for errors
         }