Get UnicodeDecoderError after salt compiled

Description of Issue

Normal salt-minion is working OK.
Salt-minion is running on a MIPS board, so I have to decrease its size, then I compile salt to pyc files and delete all the py files.

But with this compiled version of salt, salt-minion will get such error when connecting to the salt-master which runs on a x64 ubuntu system.

[CRITICAL] Unexpected error while connecting to 192.168.1.2
Traceback (most recent call last):
  File "pyvenv/lib/python3.7/site-packages/salt/minion.py", line 1036, in _connect_minion
  File "pyvenv/lib/python3.7/site-packages/salt/ext/tornado/gen.py", line 1056, in run
  File "pyvenv/lib/python3.7/site-packages/salt/ext/tornado/concurrent.py", line 239, in result
  File "<string>", line 4, in raise_exc_info
  File "pyvenv/lib/python3.7/site-packages/salt/ext/tornado/gen.py", line 1064, in run
  File "pyvenv/lib/python3.7/site-packages/salt/minion.py", line 1234, in connect_master
  File "pyvenv/lib/python3.7/site-packages/salt/ext/tornado/gen.py", line 1056, in run
  File "pyvenv/lib/python3.7/site-packages/salt/ext/tornado/concurrent.py", line 239, in result
  File "<string>", line 4, in raise_exc_info
  File "pyvenv/lib/python3.7/site-packages/salt/ext/tornado/gen.py", line 309, in wrapper
  File "pyvenv/lib/python3.7/site-packages/salt/minion.py", line 754, in eval_master
  File "pyvenv/lib/python3.7/site-packages/salt/transport/client.py", line 185, in factory
  File "pyvenv/lib/python3.7/site-packages/salt/transport/zeromq.py", line 35, in <module>
  File "pyvenv/lib/python3.7/site-packages/salt/transport/mixins/auth.py", line 16, in <module>
  File "pyvenv/lib/python3.7/site-packages/salt/master.py", line 35, in <module>
  File "pyvenv/lib/python3.7/site-packages/salt/client/ssh/__init__.py", line 195, in <module>
  File "/codecs.py", line 322, in decode
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe9 in position 12: invalid continuation byte

Setup

(Please provide relevant configs and/or SLS files (Be sure to remove sensitive info).)
compiling running on MIPS board

python3 -m compileall -b salt

Steps to Reproduce Issue

(Include debug logs if possible and relevant.)

Versions Report

(Provided by running salt --versions-report. Please also mention any differences in master/minion versions.)

Salt Version:
           Salt: 3000
 
Dependency Versions:
           cffi: Not Installed
       cherrypy: Not Installed
       dateutil: Not Installed
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
         Jinja2: 2.10.3
        libgit2: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.6.2
   mysql-python: Not Installed
      pycparser: Not Installed
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: Not Installed
         Python: 3.7.6 (default, Jan 06 2020, 16:47:09)
   python-gnupg: Not Installed
         PyYAML: 3.13
          PyZMQ: 18.1.1
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.5.3
            ZMQ: 4.3.2
 
System Versions:
           dist:   
         locale: UTF-8
        machine: mips
        release: 4.14.162
         system: Linux
        version: Not Installed

I wonder why salt of py files is ok and of pyc files gets error.

Start with the import chain shown in the traceback, especially salt/client/ssh/init.py, salt/master.py, salt/transport/mixins/auth.py, and salt/transport/zeromq.py. Reproduce the Python 3.7 compiled-only deployment using python3 -m compileall -b salt, compare it with the working source deployment, and document a verified cause and regression coverage for the UnicodeDecodeError.