Information available via 'apk info' on a package is incomplete with respect to contents of .PKGINFO.
Currently ‘apk info’ can not retrieve all information of interest on a
package, especially once Issue #7101 is implemented.
‘apk info’ (or perhaps a more direct ‘apk query’) should be able to extract any information stored in a .apk file in raw or slightly cooked form suitable for use in scripts.
(from redmine: issue id 7102, created on 2017-04-07)