diff --git a/CleanSpec.mk b/CleanSpec.mk
index a82a0bd..a93e79e 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -627,6 +627,11 @@
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/etc/adb_debug.prop)
 
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/lib*/libjavacrypto.so)
+
+# Clean up old verity tools.
+$(call add-clean-step, rm -rf $(HOST_OUT_JAVA_LIBRARIES)/BootSignature.jar)
+$(call add-clean-step, rm -rf $(HOST_OUT_JAVA_LIBRARIES)/VeritySigner.jar)
+$(call add-clean-step, rm -rf $(HOST_OUT_EXECUTABLES)/build_verity_metadata.py)
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************
diff --git a/Deprecation.md b/Deprecation.md
index 6468f46..01825b2 100644
--- a/Deprecation.md
+++ b/Deprecation.md
@@ -14,8 +14,8 @@
 
 | Module type                | State     |
 | -------------------------- | --------- |
-| `BUILD_HOST_TEST_CONFIG`   | Warning   |
-| `BUILD_TARGET_TEST_CONFIG` | Warning   |
+| `BUILD_HOST_TEST_CONFIG`   | Error     |
+| `BUILD_TARGET_TEST_CONFIG` | Error     |
 | `BUILD_*`                  | Available |
 
 ## Module Type Deprecation Process
diff --git a/core/Makefile b/core/Makefile
index 89df131..c4cd57a 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -2158,109 +2158,13 @@
 endef
 endif
 
-# Check that libraries that should only be in APEXes don't end up in the system
-# image. For the Runtime APEX this complements the checks in
-# art/build/apex/art_apex_test.py.
-# TODO(b/128708192): Implement this restriction in Soong instead.
-
-# Runtime APEX libraries
-APEX_MODULE_LIBS := \
-  libadbconnection.so \
-  libandroidicu.so \
-  libandroidio.so \
-  libart-compiler.so \
-  libart-dexlayout.so \
-  libart.so \
-  libartbase.so \
-  libartpalette.so \
-  libdexfile.so \
-  libdexfile_external.so \
-  libdexfiled_external.so \
-  libdt_fd_forward.so \
-  libdt_socket.so \
-  libicui18n.so \
-  libicuuc.so \
-  libjavacore.so \
-  libjdwp.so \
-  libnativebridge.so \
-  libnativehelper.so \
-  libnativeloader.so \
-  libnpt.so \
-  libopenjdk.so \
-  libopenjdkjvm.so \
-  libopenjdkjvmti.so \
-  libpac.so \
-  libprofile.so \
-  libsigchain.so \
-
-# Conscrypt APEX libraries
-APEX_MODULE_LIBS += \
-  libjavacrypto.so \
-
-# An option to disable the check below, for local use since some build targets
-# still may create these libraries in /system (b/129006418).
-DISABLE_APEX_LIBS_ABSENCE_CHECK ?=
-
-# Exclude lib/arm and lib/arm64 which contain the native bridge proxy libs.
-# They are compiled for the guest architecture and used with an entirely
-# different linker config. The native libs are then linked to as usual via
-# exported interfaces, so the proxy libs do not violate the interface boundaries
-# on the native architecture.
-# TODO(b/130630776): Introduce a make variable for the appropriate directory
-# when native bridge is active.
-APEX_LIBS_ABSENCE_CHECK_EXCLUDE := lib/arm lib/arm64
-
-# Exclude vndk-sp-* subdirectories which contain prebuilts from older releases.
-APEX_LIBS_ABSENCE_CHECK_EXCLUDE += lib/vndk-% lib64/vndk-%
-
-# If the check below fails, some library has ended up in system/lib or
-# system/lib64 that is intended to only go into some APEX package. The likely
-# cause is that a library or binary in /system has grown a dependency that
-# directly or indirectly pulls in the prohibited library.
-#
-# To resolve this, look for the APEX package that the library belong to - search
-# for it in 'native_shared_lib' properties in 'apex' build modules (see
-# art/build/apex/Android.bp for an example). Then check if there is an exported
-# library in that APEX package that should be used instead, i.e. one listed in
-# its 'native_shared_lib' property for which the corresponding 'cc_library'
-# module has a 'stubs' clause (like libdexfile_external in
-# art/libdexfile/Android.bp).
-#
-# If you cannot find an APEX exported library that fits your needs, or you think
-# that the library you want to depend on should be allowed in /system, then
-# please contact the owners of the APEX package containing the library.
-#
-# If you get this error for a library that is exported in an APEX, then the APEX
-# might be misconfigured or something is wrong in the build system. Please reach
-# out to the APEX package owners and/or soong-team@, or
-# android-building@googlegroups.com externally.
-ifndef DISABLE_APEX_LIBS_ABSENCE_CHECK
-define check-apex-libs-absence
-$(hide) ( \
-  cd $(TARGET_OUT) && \
-  findres=$$(find lib* \
-    $(foreach dir,$(APEX_LIBS_ABSENCE_CHECK_EXCLUDE),-path "$(subst %,*,$(dir))" -prune -o) \
-    -type f \( -false $(foreach lib,$(APEX_MODULE_LIBS),-o -name $(lib)) \) \
-    -print) && \
-  if [ -n "$$findres" ]; then \
-    echo "APEX libraries found in system image (see comment in build/make/core/Makefile for details):" 1>&2; \
-    echo "$$findres" | sort 1>&2; \
-    false; \
-  fi; \
-)
-endef
-else
-define check-apex-libs-absence
-endef
-endif
-
 # $(1): output file
 define build-systemimage-target
   @echo "Target system fs image: $(1)"
   $(call create-system-vendor-symlink)
   $(call create-system-product-symlink)
   $(call create-system-product_services-symlink)
-  $(call check-apex-libs-absence)
+  $(call check-apex-libs-absence-on-disk)
   @mkdir -p $(dir $(1)) $(systemimage_intermediates) && rm -rf $(systemimage_intermediates)/system_image_info.txt
   $(call generate-image-prop-dictionary, $(systemimage_intermediates)/system_image_info.txt,system, \
       skip_fsck=true)
@@ -3565,8 +3469,8 @@
   $(HOST_OUT_EXECUTABLES)/bsdiff \
   $(HOST_OUT_EXECUTABLES)/imgdiff \
   $(HOST_OUT_JAVA_LIBRARIES)/signapk.jar \
-  $(HOST_OUT_JAVA_LIBRARIES)/BootSignature.jar \
-  $(HOST_OUT_JAVA_LIBRARIES)/VeritySigner.jar \
+  $(HOST_OUT_JAVA_LIBRARIES)/boot_signer.jar \
+  $(HOST_OUT_JAVA_LIBRARIES)/verity_signer.jar \
   $(HOST_OUT_EXECUTABLES)/mke2fs \
   $(HOST_OUT_EXECUTABLES)/mkuserimg_mke2fs \
   $(HOST_OUT_EXECUTABLES)/e2fsdroid \
diff --git a/core/config.mk b/core/config.mk
index 94928a2..bf59fb1 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -604,7 +604,7 @@
 BUILD_IMAGE_SRCS := $(wildcard build/make/tools/releasetools/*.py)
 APPEND2SIMG := $(HOST_OUT_EXECUTABLES)/append2simg
 VERITY_SIGNER := $(HOST_OUT_EXECUTABLES)/verity_signer
-BUILD_VERITY_METADATA := $(HOST_OUT_EXECUTABLES)/build_verity_metadata.py
+BUILD_VERITY_METADATA := $(HOST_OUT_EXECUTABLES)/build_verity_metadata
 BUILD_VERITY_TREE := $(HOST_OUT_EXECUTABLES)/build_verity_tree
 BOOT_SIGNER := $(HOST_OUT_EXECUTABLES)/boot_signer
 FUTILITY := $(HOST_OUT_EXECUTABLES)/futility-host
diff --git a/core/deprecation.mk b/core/deprecation.mk
index cbc938a..9d57527 100644
--- a/core/deprecation.mk
+++ b/core/deprecation.mk
@@ -37,13 +37,13 @@
 # relevant BUILD_BROKEN_USES_BUILD_* variables, then these would move to
 # DEFAULT_ERROR_BUILD_MODULE_TYPES.
 DEFAULT_WARNING_BUILD_MODULE_TYPES :=$= \
-  BUILD_HOST_TEST_CONFIG \
-  BUILD_TARGET_TEST_CONFIG \
 
 # These are BUILD_* variables that are errors to reference, but you can set
 # BUILD_BROKEN_USES_BUILD_* in your BoardConfig.mk in order to turn them back
 # to warnings.
 DEFAULT_ERROR_BUILD_MODULE_TYPES :=$= \
+  BUILD_HOST_TEST_CONFIG \
+  BUILD_TARGET_TEST_CONFIG \
 
 # These are BUILD_* variables that are always errors to reference.
 # Setting the BUILD_BROKEN_USES_BUILD_* variables is also an error.
diff --git a/core/main.mk b/core/main.mk
index 7e1bdd5..6f92ff1 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -1200,6 +1200,117 @@
 )
 endef
 
+# Check that libraries that should only be in APEXes don't end up in the system
+# image. For the Runtime APEX this complements the checks in
+# art/build/apex/art_apex_test.py.
+# TODO(b/128708192): Implement this restriction in Soong instead.
+
+# Runtime APEX libraries
+APEX_MODULE_LIBS := \
+  libadbconnection.so \
+  libandroidicu.so \
+  libandroidio.so \
+  libart-compiler.so \
+  libart-dexlayout.so \
+  libart.so \
+  libartbase.so \
+  libartpalette.so \
+  libdexfile.so \
+  libdexfile_external.so \
+  libdexfiled_external.so \
+  libdt_fd_forward.so \
+  libdt_socket.so \
+  libicui18n.so \
+  libicuuc.so \
+  libjavacore.so \
+  libjdwp.so \
+  libnativebridge.so \
+  libnativehelper.so \
+  libnativeloader.so \
+  libnpt.so \
+  libopenjdk.so \
+  libopenjdkjvm.so \
+  libopenjdkjvmti.so \
+  libpac.so \
+  libprofile.so \
+  libsigchain.so \
+
+# Conscrypt APEX libraries
+APEX_MODULE_LIBS += \
+  libjavacrypto.so \
+
+# An option to disable the check below, for local use since some build targets
+# still may create these libraries in /system (b/129006418).
+DISABLE_APEX_LIBS_ABSENCE_CHECK ?=
+
+# Exclude lib/arm and lib/arm64 which contain the native bridge proxy libs. They
+# are compiled for the guest architecture and used with an entirely different
+# linker config. The native libs are then linked to as usual via exported
+# interfaces, so the proxy libs do not violate the interface boundaries on the
+# native architecture.
+# TODO(b/130630776): Introduce a make variable for the appropriate directory
+# when native bridge is active.
+APEX_LIBS_ABSENCE_CHECK_EXCLUDE := lib/arm lib/arm64
+
+# Exclude vndk-* subdirectories which contain prebuilts from older releases.
+APEX_LIBS_ABSENCE_CHECK_EXCLUDE += lib/vndk-% lib64/vndk-%
+
+ifdef DISABLE_APEX_LIBS_ABSENCE_CHECK
+  check-apex-libs-absence :=
+  check-apex-libs-absence-on-disk :=
+else
+  # If the check below fails, some library has ended up in system/lib or
+  # system/lib64 that is intended to only go into some APEX package. The likely
+  # cause is that a library or binary in /system has grown a dependency that
+  # directly or indirectly pulls in the prohibited library.
+  #
+  # To resolve this, look for the APEX package that the library belong to -
+  # search for it in 'native_shared_lib' properties in 'apex' build modules (see
+  # art/build/apex/Android.bp for an example). Then check if there is an
+  # exported library in that APEX package that should be used instead, i.e. one
+  # listed in its 'native_shared_lib' property for which the corresponding
+  # 'cc_library' module has a 'stubs' clause (like libdexfile_external in
+  # art/libdexfile/Android.bp).
+  #
+  # If you cannot find an APEX exported library that fits your needs, or you
+  # think that the library you want to depend on should be allowed in /system,
+  # then please contact the owners of the APEX package containing the library.
+  #
+  # If you get this error for a library that is exported in an APEX, then the
+  # APEX might be misconfigured or something is wrong in the build system.
+  # Please reach out to the APEX package owners and/or soong-team@, or
+  # android-building@googlegroups.com externally.
+  define check-apex-libs-absence
+    $(call maybe-print-list-and-error, \
+      $(filter $(foreach lib,$(APEX_MODULE_LIBS),%/$(lib)), \
+        $(filter-out $(foreach dir,$(APEX_LIBS_ABSENCE_CHECK_EXCLUDE), \
+                       $(TARGET_OUT)/$(if $(findstring %,$(dir)),$(dir),$(dir)/%)), \
+          $(filter $(TARGET_OUT)/lib/% $(TARGET_OUT)/lib64/%,$(1)))), \
+      APEX libraries found in system image (see comment for check-apex-libs-absence in \
+      build/make/core/main.mk for details))
+  endef
+
+  # TODO(b/129006418): The check above catches libraries through product
+  # dependencies visible to make, but as long as they have install rules in
+  # /system they may still be created there through other make targets. To catch
+  # that we also do a check on disk just before the system image is built.
+  define check-apex-libs-absence-on-disk
+    $(hide) ( \
+      cd $(TARGET_OUT) && \
+      findres=$$(find lib* \
+        $(foreach dir,$(APEX_LIBS_ABSENCE_CHECK_EXCLUDE),-path "$(subst %,*,$(dir))" -prune -o) \
+        -type f \( -false $(foreach lib,$(APEX_MODULE_LIBS),-o -name $(lib)) \) \
+        -print) && \
+      if [ -n "$$findres" ]; then \
+        echo "APEX libraries found in system image (see comment for check-apex-libs-absence" 1>&2; \
+        echo "in build/make/core/main.mk for details):" 1>&2; \
+        echo "$$findres" | sort 1>&2; \
+        false; \
+      fi; \
+    )
+  endef
+endif
+
 ifdef FULL_BUILD
   ifneq (true,$(ALLOW_MISSING_DEPENDENCIES))
     # Check to ensure that all modules in PRODUCT_PACKAGES exist (opt in per product)
@@ -1312,6 +1423,8 @@
 	rm -f $@
 	$(foreach f,$(sort $(all_offending_files)),echo $(f) >> $@;)
   endif
+
+  $(call check-apex-libs-absence,$(product_target_FILES))
 else
   # We're not doing a full build, and are probably only including
   # a subset of the module makefiles.  Don't try to build any modules
diff --git a/tools/releasetools/verity_utils.py b/tools/releasetools/verity_utils.py
index 3a58755..3063800 100644
--- a/tools/releasetools/verity_utils.py
+++ b/tools/releasetools/verity_utils.py
@@ -52,7 +52,7 @@
 
 
 def GetVerityMetadataSize(image_size):
-  cmd = ["build_verity_metadata.py", "size", str(image_size)]
+  cmd = ["build_verity_metadata", "size", str(image_size)]
   output = common.RunAndCheckOutput(cmd, verbose=False)
   return int(output)
 
@@ -97,7 +97,7 @@
 def BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
                         block_device, signer_path, key, signer_args,
                         verity_disable):
-  cmd = ["build_verity_metadata.py", "build", str(image_size),
+  cmd = ["build_verity_metadata", "build", str(image_size),
          verity_metadata_path, root_hash, salt, block_device, signer_path, key]
   if signer_args:
     cmd.append("--signer_args=\"%s\"" % (' '.join(signer_args),))