sudo zypper in libmp3splt0-mp3 libmp3splt0-ogg
So, after all, I'd expect to see an error message, when trying to create a setup message. The whole point of using a smartcard is to not be able to export keys. Currently enigmail only checks whether the 'gpg2 --export-secret-keys' completest successfully, which, as you can see above, it does. There needs to be an additional check to test whether there are actual keys or just stubs.
gnupg exports the following stuff: > gpg2 --export-secret-keys CAF707C1 | gpg2 --list-packets :secret key packet: version 4, algo 1, created 1288368370, expires 0 skey[0]: [2048 bits] skey[1]: [17 bits] gnu-dummy S2K, algo: 0, simple checksum, hash: 0 protect IV: keyid: CCF49B90CAF707C1 :user ID packet: "Adam Mizerski <adam@mizerski.pl>" :signature packet: algo 1, keyid CCF49B90CAF707C1 version 4, created 1507407585, md5len 0, sigclass 0x13 digest algo 8, begin of digest 64 b5 hashed subpkt 27 len...
Debug log file won't tell you much. From enigmails point of view everything looks correctly. The problem is that 'gpg2 --export-secret-keys' does not complain about missing master key, nor subkeys being transferred to a smartcard. Before doing this enigmail should check for the status of the key. For example 'gpg2 --list-secret-keys' shows: sec# 2048R/CAF707C1 2010-10-29 [expires: 2018-10-07] uid Adam Mizerski <adam@mizerski.pl> uid Adam Mizerski <etampl@opensuse.org> ssb> 2048R/CE91DA75 2010-10-29...
getMinimalPubKey requires gnupg 2.1.10
I have a similar problem, but with a bit different situation. I have a setup with Yubikey, where subkeys keys are on smartcard and master key is not available at all. When creating setup message, enigmail calls 'gpg ... --export-secret-keys 0xKEYID', which successfully exports some data (I'm not sure what exactly). Then delta chat obviously has problem with importing secret keys, because there are none.