diff --git a/make/projects-dir.mk b/make/projects-dir.mk
index 4916dab0..5539ad4f 100644
--- a/make/projects-dir.mk
+++ b/make/projects-dir.mk
@@ -63,11 +63,11 @@ export JW_PKG_VERBOSE
 # ------------ external programs I
 
 CWD                         := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
-GET_OS_SH                    = /bin/bash $(firstword $(wildcard $(JWB_SCRIPT_DIR)/get-os.sh $(JW_PKG_BINDIR)/get-os.sh) get-os-sh-not-found)
+JW_PKG_PY                    = python3 $(JWB_SCRIPT_DIR)/jw-pkg.py --prefix $(shell pwd) $(JW_PKG_PY_EXTRA_OPTS)
 SSH_WRAPPER_SH              := $(CWD)/ssh-wrapper.sh
 
 EXCLUDES_FILE               ?= exclude.txt
-EXCLUDES_FILES               = $(wildcard exclude-$(shell $(GET_OS_SH) name 2>/dev/null).txt exclude-$(shell $(GET_OS_SH) 2>/dev/null).txt $(EXCLUDES_FILE))
+EXCLUDES_FILES               = $(wildcard $(patsubst %,exclude-%.txt,$(shell $(JW_PKG_PY) distro info --format '%{cascade}')) $(EXCLUDES_FILE))
 ifneq ($(EXCLUDES_FILES),)
   EXCLUDE_FROM_BUILD        += $(shell sed 's/\#.*//g' $(EXCLUDES_FILES))
 endif
@@ -113,10 +113,9 @@ ifeq ($(TIME),)
     TIME                    += -p
   endif
 endif
-JW_PKG_PY                    = $(TIME) python3 $(JWB_SCRIPT_DIR)/jw-pkg.py --prefix $(shell pwd) $(JW_PKG_PY_EXTRA_OPTS)
-JW_PKG_PY_PROJECTS           = $(JW_PKG_PY) projects
+JW_PKG_PY_PROJECTS           = $(TIME) $(JW_PKG_PY) projects
 JW_PKG_PY_BUILD              = $(JW_PKG_PY_PROJECTS) build $(JW_PKG_PY_EXTRA_BUILD_OPTS)
-PKG_MANAGER                 ?= $(JW_PKG_PY) distro --interactive=$(INTERACTIVE)
+PKG_MANAGER                 ?= $(TIME) $(JW_PKG_PY) distro --interactive=$(INTERACTIVE)
 
 ifneq ($(origin PROJECTS_DIR_REMOTE_BASE),undefined)
   PGIT_SH                   += --remote-base $(PROJECTS_DIR_REMOTE_BASE)
@@ -192,7 +191,7 @@ echo-install-deps:
 echo-release-deps:
 	$(Q)$(JW_PKG_PY_PROJECTS) required-os-pkg --quote --skip-excluded --flavours "build run release" $(TARGET_PROJECTS)
 echo-os:
-	$(Q)$(GET_OS_SH)
+	$(Q)$(JW_PKG_PY) distro info
 
 echo-projects:
 	@echo $(PROJECTS)