How to perform freebsd-update from STABLE

Sometimes freebsd-update doesn't want to update from -STABLE system. Error received would be

Looking up update.FreeBSD.org mirrors... 3 mirrors found.
Fetching public key from update1.freebsd.org... failed.
Fetching public key from update2.freebsd.org... failed.
Fetching public key from dualstack.aws.update.freebsd.org... failed.
No mirrors remaining, giving up.


Way to fix this error is to force freebsd-update to treat -STABLE the same way as -RELEASE. If uname returns for example

FreeBSD ***** 10.3-STABLE FreeBSD 10.3-STABLE *****

then you can make freebsd-update treat it as 10.3-RELEASE like this:

env UNAME_r=10.3-RELEASE freebsd-update -r 14.0-RELEASE upgrade