gpg 2.1.15, *no* keyservers found for submit/recv, "DNS query returned an error or no records: No such domain (nxdomain)"

[lists at ssl-mail.com]

instead of polluting the bug report with noise, I'll keep my response here.

When I try tro reproduce your tests,  I'm still getting the "No keyserver available" biz, but not seeing all the other detail you do.

rpm -qa | egrep -i gpg2
	gpg2-lang-2.1.15-197.2.noarch
	gpg2-2.1.15-197.2.x86_64

gpg2 --version
	gpg (GnuPG) 2.1.15
	libgcrypt 1.7.3
	Copyright (C) 2016 Free Software Foundation, Inc.
	License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>
	This is free software: you are free to change and redistribute it.
	There is NO WARRANTY, to the extent permitted by law.

	Home: /root/.gnupg
	Supported algorithms:
	Pubkey: RSA, ELG, DSA, ECDH, ECDSA, EDDSA
	Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
	        CAMELLIA128, CAMELLIA192, CAMELLIA256
	Hash: SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
	Compression: Uncompressed, ZIP, ZLIB, BZIP2

dirmngr --version
	dirmngr (GnuPG) 2.1.15
	Copyright (C) 2016 Free Software Foundation, Inc.
	License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>
	This is free software: you are free to change and redistribute it.
	There is NO WARRANTY, to the extent permitted by law.

GNUPGHOME=$(mktemp -d) gpg-connect-agent --dirmngr 
	gpg-connect-agent: no running Dirmngr - starting '/usr/bin/dirmngr'
	gpg-connect-agent: waiting for the dirmngr to come up ... (5s)
	gpg-connect-agent: connection to the dirmngr established
	> getinfo dnsinfo
		OK - ADNS w/o Tor support
	> getinfo tor
		ERR 167772416 False <Dirmngr> - Tor mode is NOT enabled
	> keyserver --clear
		OK
	> keyserver hkps://hkps.pool.sks-keyservers.net
		OK
	> keyserver --resolve hkps://hkps.pool.sks-keyservers.net
		S # https://hkps.pool.sks-keyservers.net:443
		OK
	> keyserver --hosttable
		S # hosttable (idx, ipv6, ipv4, dead, name, time):
		S #   0       hkps.pool.sks-keyservers.net
		OK
	>

gpg -v --debug-all --recv-keys 0x673A03E4C1DB921F
	gpg: reading options from '/root/.gnupg/gpg.conf'
	gpg: enabled debug flags: packet mpi crypto filter iobuf memory cache memstat trust hashing cardio ipc clock lookup extprog
	gpg: DBG: [not enabled in the source] start
	gpg: no running Dirmngr - starting '/usr/bin/dirmngr'
	gpg: waiting for the dirmngr to come up ... (5s)
	gpg: DBG: chan_3 <- # Home: /root/.gnupg
	gpg: DBG: chan_3 <- # Config: /root/.gnupg/dirmngr.conf
	gpg: DBG: chan_3 <- OK Dirmngr 2.1.15 at your service
	gpg: connection to the dirmngr established
	gpg: DBG: chan_3 -> GETINFO version
	gpg: DBG: chan_3 <- D 2.1.15
	gpg: DBG: chan_3 <- OK
	gpg: DBG: chan_3 -> KEYSERVER --clear hkps://hkps.pool.sks-keyservers.net:443
	gpg: DBG: chan_3 <- OK
	gpg: DBG: chan_3 -> KS_GET -- 0x673A03E4C1DB921F
>>>	gpg: DBG: chan_3 <- ERR 167772346 No keyserver available <Dirmngr>
>>>	gpg: keyserver receive failed: No keyserver available
	gpg: DBG: chan_3 -> BYE
	gpg: DBG: [not enabled in the source] stop
	gpg: random usage: poolsize=600 mixed=0 polls=0/0 added=0/0
	              outmix=0 getlvl1=0/0 getlvl2=0/0
	gpg: secmem usage: 0/65536 bytes in 0 blocks