I'm using the SDK (on docker) and found a problem with autorebuilds. Since 19.07.5 including 21.02.0 the zlib package is rebuilt each time i run make package/zlib/compile, which also triggers a rebuild of packages that depend on zlib, for example ncurses.
A work-around is to patch include/package.mk as shown below, which reverts a change from commit 605adb10 "download: handle possibly invalid local tarballs":
$ diff -u include/package.mk{.orig,}
--- include/package.mk.orig 2021-09-07 18:31:27.463442970 +0000
+++ include/package.mk 2021-09-07 19:26:08.390457191 +0000
@@ -185,7 +185,7 @@
$(call Build/Autoclean)
$(call DefaultTargets)
- $(DL_DIR)/$(FILE): FORCE
+# $(DL_DIR)/$(FILE): FORCE
download:
$(foreach hook,$(Hooks/Download),