I use salt to manage a mixture of Leap and Tumbleweed hosts. Because
salt-minions can connect to newer masters, but not the other way around, I use
Tumbleweed to host my master.

Since the recent upgrade to

    salt-minion-3002.2-150300.53.10.1.x86_64

on my Leap minions, they fail to connect to the master, with the following
error (somewhat cut down, as indicated by ellipsis):


Apr 02 13:22:51 dogprod salt-minion[9971]: [ERROR   ] Error while bringing up
minion for multi-master. Is master at master1 responding?
Apr 02 13:23:01 dogprod salt-minion[9971]: [ERROR   ] Sign-in attempt failed:
{'enc': 'pub', 'pub_key': '-----BEGIN PUBLIC
KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAzS6pLmz10lMkgNZVUauW\nMv3GvjpiR+pQQzgXP9qgTJHhb01Hw2MM0ociT2a+GjLFq6fF9PHQ9DHDUM0aw55+\n7LYIUbrdZJ1n8J02Sknd5pfZdDjOGzsI6t409loNX98FD9EI7m1jP4iCzeSFmjrG\nWU0ZGUw2Th58ZE7zn+CFiy7Sws/B/D2yIRoKB58v+Cri9pUJMmA7T/e2/JGEKPle\nz8ENYYmx21AlTgyLZibPc7T17LgiF7od+sTlSKYW9Y/q0pKR/ZUJb9I9YIdh/eDS\nYz2cz5h41F9qMfoZFYJ0Ao6DVbAw2KbNq9Hkwyq+qdLTwEAO7AX0mbJyNlOlRK4V\n5QIDAQAB\n-----END
PUBLIC KEY-----\n', 'publish_port': 4505, 'token':
b"\xd6\xc75.$\n\x02\xb8\x9b\t\x89[\xe8\xbag@\x9f\xdaW\xc6\x95\xe5iB\xfd\x06\x98fD\nd}...",
'aes':
b'\xa1\xab\xceu\x1eg;g\xe3\xe0\xd8\xf4g\xc7\x93\xb2\xfd\xab\xa8`\x00\xb7\xee\xee\x0f(}V|6(\x9d)\x0e\xf3...',
'sig': b'!J\xd6\xa1\x9c\xe2\xa4\xd2p\x1a\x91\x02\xeek\xae-\x95\xa1\x8b...'}


I have tried to clear all caches and start with freshly generated PKI material,
but it doesn't help.

The minion configuration is minimal:

    state_output: changes
    state_output_diff: True
    master: master1

The master configuration is similarly sparse, except it also defines some GitFS
sources for states and pillar data.


Reverting the Leap minions back to 

    salt-minion-3002.2-150300.53.7.2.x86_64

fixes the issue.