seems like the cache is not cleaned properly with apk clean:

apk-tools 2.4.3, compiled for x86_64

localhost:~# apk add cpufreqd
(1/1) Installing cpufreqd (2.4.2-r2)
Executing busybox-1.21.1-r0.trigger
Executing uclibc-utils-0.9.33.2-r27.trigger
1 errors; 79 MiB in 56 packages

 apk del --purge cpufreqd
(1/1) Purging cpufreqd (2.4.2-r2)
Executing busybox-1.21.1-r0.trigger
Executing uclibc-utils-0.9.33.2-r27.trigger
1 errors; 79 MiB in 55 packages


localhost:/media/usb/cache# apk cache clean
localhost:/media/usb/cache# apk cache sync -v
localhost:/media/usb/cache# ls
APKINDEX.cfc83ca2.tar.gz          cpufrequtils-008-r1.68973c95.apk  elinks-0.12_pre6-r0.7984c931.apk  hostapd-2.0-r0.6b6b7f88.apk       libnl-1.1.4-r0.a306b70d.apk
cpufreqd-2.4.2-r2.f6e5718f.apk    dropbear-2013.58-r0.9f3b512b.apk  hdparm-9.43-r0.a8bbe0f4.apk       installed

(from redmine: issue id 2889, created on 2014-05-15, closed on 2015-12-09)

• Changesets:
  • Revision f2d9a144 by Timo Teräs on 2014-10-06T14:54:52Z:

cache: delete more aggressively unneeded cached files

Also if --purge is specified delete all uninstalled packages.
Fixes #2889