diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index d22f55af2..9e68170ce 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -142,6 +142,7 @@ build_esp_idf_tests:
   script:
     # it's not possible to build 100% out-of-tree and have the "artifacts"
     # mechanism work, but this is the next best thing
+    - rm -rf build_examples
     - mkdir build_examples
     - cd build_examples
     # build some of examples
@@ -162,6 +163,12 @@ build_examples_03:
 build_examples_04:
   <<: *build_examples_template
 
+build_examples_05:
+  <<: *build_examples_template
+
+build_examples_06:
+  <<: *build_examples_template
+
 build_docs:
   stage: build
   image: $CI_DOCKER_REGISTRY/esp32-ci-env
@@ -228,8 +235,11 @@ test_build_system:
     - build_test
   dependencies: []
   script:
-    - ./tools/ci/test_configure_ci_environment.sh
-    - ./tools/ci/test_build_system.sh
+    - ${IDF_PATH}/tools/ci/test_configure_ci_environment.sh
+    - rm -rf test_build_system
+    - mkdir test_build_system
+    - cd test_build_system
+    - ${IDF_PATH}/tools/ci/test_build_system.sh
 
 test_report:
   stage: test_report
diff --git a/components/bootloader/Makefile.projbuild b/components/bootloader/Makefile.projbuild
index a8c10067b..7a35dc8ad 100644
--- a/components/bootloader/Makefile.projbuild
+++ b/components/bootloader/Makefile.projbuild
@@ -118,6 +118,6 @@ ifndef CONFIG_SECURE_BOOT_ENABLED
 all_binaries: $(BOOTLOADER_BIN)
 endif
 
-bootloader-clean:
+bootloader-clean: $(SDKCONFIG_MAKEFILE)
 	$(BOOTLOADER_MAKE) app-clean
 	rm -f $(SECURE_BOOTLOADER_KEY) $(BOOTLOADER_DIGEST_BIN)
diff --git a/make/project.mk b/make/project.mk
index d2f3cfcd5..d22a1b1dd 100644
--- a/make/project.mk
+++ b/make/project.mk
@@ -45,10 +45,18 @@ help:
 # dependency checks
 ifndef MAKE_RESTARTS
 ifeq ("$(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))", "")
+$(error esp-idf build system doesn't support running 'clean' targets along with any others. Run 'make clean' and then run other targets separately.)
+endif
+endif
+
+
 # make IDF_PATH a "real" absolute path
 # * works around the case where a shell character is embedded in the environment variable value.
 # * changes Windows-style C:/blah/ paths to MSYS/Cygwin style /c/blah
@@ -361,10 +369,10 @@ endef
 define GenerateComponentTargets
 .PHONY: component-$(2)-build component-$(2)-clean
 
-component-$(2)-build: check-submodules
+component-$(2)-build: check-submodules $(call prereq_if_explicit, component-$(2)-clean) | $(BUILD_DIR_BASE)/$(2)
 	$(call ComponentMake,$(1),$(2)) build
 
-component-$(2)-clean:
+component-$(2)-clean: | $(BUILD_DIR_BASE)/$(2) $(BUILD_DIR_BASE)/$(2)/component_project_vars.mk
 	$(call ComponentMake,$(1),$(2)) clean
 
 $(BUILD_DIR_BASE)/$(2):
@@ -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
-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.
diff --git a/make/project_config.mk b/make/project_config.mk
index c0369f95f..c92d5292e 100644
--- a/make/project_config.mk
+++ b/make/project_config.mk
@@ -21,9 +21,9 @@ $(KCONFIG_TOOL_DIR)/mconf $(KCONFIG_TOOL_DIR)/conf:
 	$(MAKE) -C $(KCONFIG_TOOL_DIR)
 
 ifeq ("$(wildcard $(SDKCONFIG))","")
-ifeq ("$(filter defconfig, $(MAKECMDGOALS))","")
-# if no configuration file is present and defconfig is not a named
-# target, run defconfig then menuconfig to get the initial config
+ifeq ("$(filter defconfig clean% %clean, $(MAKECMDGOALS))","")
+# if no configuration file is present and defconfig or clean
+# is not a named target, run defconfig then menuconfig to get the initial config
 $(SDKCONFIG): menuconfig
 menuconfig: defconfig
 else
diff --git a/tools/ci/build_examples.sh b/tools/ci/build_examples.sh
index 8cdb05ae5..c22aaf4bd 100755
--- a/tools/ci/build_examples.sh
+++ b/tools/ci/build_examples.sh
@@ -5,7 +5,7 @@
 #
 # Runs as part of CI process.
 #
-# Assumes CWD is an out-of-tree build directory, and will copy examples
+# Assumes PWD is an out-of-tree build directory, and will copy examples
 # to individual subdirectories, one by one.
 #
 #
@@ -44,6 +44,8 @@ die() {
 
 [ -z ${IDF_PATH} ] && die "IDF_PATH is not set"
 
+echo "build_examples running in ${PWD}"
+
 # only 0 or 1 arguments
 [ $# -le 1 ] || die "Have to run as $(basename $0) [<JOB_NAME>]"
 
@@ -55,7 +57,7 @@ RESULT=0
 FAILED_EXAMPLES=""
 
 RESULT_WARNINGS=22  # magic number result code for "warnings found"
-LOG_WARNINGS=$(mktemp -t example_all.XXXX.log)
+LOG_WARNINGS=${PWD}/build_warnings.log
 
 if [ $# -eq 0 ]
 then
@@ -114,9 +116,10 @@ build_example () {
         # build non-verbose first
         local BUILDLOG=${PWD}/examplebuild.${ID}.log
         (
-            MAKEFLAGS= make clean defconfig &> >(tee -a "${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
         }
diff --git a/tools/ci/test_build_system.sh b/tools/ci/test_build_system.sh
index 0f2472422..e7a3c7316 100755
--- a/tools/ci/test_build_system.sh
+++ b/tools/ci/test_build_system.sh
@@ -3,11 +3,12 @@
 # Test the build system for basic consistency
 #
 # A bash script that tests some likely make failure scenarios in a row
-# Creates its own test build directory under TMP and cleans it up when done.
+#
+# Assumes PWD is an out-of-tree build directory, and will create a
+# subdirectory inside it to run build tests in.
 #
 # Environment variables:
 # IDF_PATH - must be set
-# TMP - can override /tmp location for build directory
 # ESP_IDF_TEMPLATE_GIT - Can override git clone source for template app. Otherwise github.
 # NOCLEANUP - Set to '1' if you want the script to leave its temporary directory when done, for post-mortem.
 #
@@ -26,7 +27,6 @@
 
 # Set up some variables
 #
-[ -z ${TMP} ] && TMP="/tmp"
 # override ESP_IDF_TEMPLATE_GIT to point to a local dir if you're testing and want fast iterations
 [ -z ${ESP_IDF_TEMPLATE_GIT} ] && ESP_IDF_TEMPLATE_GIT=https://github.com/espressif/esp-idf-template.git
 
@@ -205,7 +205,7 @@ function failure()
     FAILURES="${FAILURES}${STATUS} :: $1\n"
 }
 
-TESTDIR=${TMP}/build_system_tests_$$
+TESTDIR=${PWD}/build_system_tests_$$
 mkdir -p ${TESTDIR}
 # set NOCLEANUP=1 if you want to keep the test directory around
 # for post-mortem debugging