$ gpgsm --import crlf.pem
gpgsm: invalid radix64 character 2d skipped
gpgsm: invalid radix64 character 2d skipped
gpgsm: invalid radix64 character 2d skipped
gpgsm: invalid radix64 character 2d skipped
gpgsm: invalid radix64 character 2d skipped
gpgsm: total number processed: 0
This happens when crlf.pem contains CR+LF line endings. It works fine with just LF.
Use case from http://lists.wald.intevation.org/pipermail/gpg4win-users-en/2020-February/001607.html is importing certificates from openkeys.de