[BUG] Tornado UnicodeDecodeError behind proxy

[nathanmetcalf]

Description
Downloading some files behind a proxy causes the below error:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfd in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xba in position 2: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xf0 in position 0: invalid continuation byte

---=== TRIM ===---

This is only for some files. This URL (On the same server) does not error.

http://archive.ubuntu.com/ubuntu/dists/focal-updates/Release

Setup
Salt minion config:

proxy_port: 3128
proxy_host: <proxy server>

State file

download_proxy_test:
  file.managed:
    - name: /tmp/test.download
     - source: http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dep11/Components-amd64.yml.xz
    - skip_verify: true
    - keep_source: false

Squid proxy config

http_port 3128
visible_hostname proxy1.local
access_log syslog:daemon.info
cache_log syslog:daemon.info
http_access allow all

Please be as specific as possible and give set-up details.

• on-prem machine
• VM - Virtualbox
• VM running on a cloud service, AWS
• container (Kubernetes, Docker, containerd, etc. please specify)
• or a combination, please be explicit
• jails if it is FreeBSD
• classic packaging
• onedir packaging
• used bootstrap to install

Steps to Reproduce the behavior

Debug Logs

Debug

[DEBUG   ] In saltenv 'base', looking at rel_path 'default/proxy.sls' to resolve 'salt://default/proxy.sls'
[DEBUG   ] In saltenv 'base', ** considering ** path '/var/cache/salt/minion/files/base/default/proxy.sls' to resolve 'salt://default/proxy.sls'
[DEBUG   ] compile template: /var/cache/salt/minion/files/base/default/proxy.sls
[DEBUG   ] Jinja search path: ['/var/cache/salt/minion/files/base']
[DEBUG   ] Using importlib_metadata to load entry points
[DEBUG   ] LazyLoaded roots.envs
[DEBUG   ] Could not LazyLoad roots.init: 'roots.init' is not available.
[PROFILE ] Time (in seconds) to render '/var/cache/salt/minion/files/base/default/proxy.sls' using 'jinja' renderer: 0.04261612892150879
[DEBUG   ] Rendered data from file: /var/cache/salt/minion/files/base/default/proxy.sls:
download_proxy_test:
  file.managed:
    - name: /tmp/test.download
    - source: http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dep11/Components-amd64.yml.xz
    - skip_verify: true
    - keep_source: false

[DEBUG   ] Results of YAML rendering:
OrderedDict([('download_proxy_test', OrderedDict([('file.managed', [OrderedDict([('name', '/tmp/test.download')]), OrderedDict([('source', 'http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dep11/Components-amd64.yml.xz')]), OrderedDict([('skip_verify', True)]), OrderedDict([('keep_source', False)])])]))])
[PROFILE ] Time (in seconds) to render '/var/cache/salt/minion/files/base/default/proxy.sls' using 'yaml' renderer: 0.00148773193359375
[DEBUG   ] LazyLoaded config.option
[DEBUG   ] LazyLoaded file.managed
[INFO    ] Running state [/tmp/test.download] at time 13:46:12.824547
[INFO    ] Executing state file.managed for [/tmp/test.download]
[DEBUG   ] LazyLoaded file.source_list
[DEBUG   ] LazyLoaded cp.is_cached
[DEBUG   ] LazyLoaded roots.envs
[DEBUG   ] Could not LazyLoad roots.init: 'roots.init' is not available.
[DEBUG   ] Requesting URL http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dep11/Components-amd64.yml.xz using GET method
[DEBUG   ] Using backend: tornado
[DEBUG   ] GET http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dep11/Components-amd64.yml.xz
[DEBUG   ] Trying 10.0.14.11:3128...
[DEBUG   ] TCP_NODELAY set
[DEBUG   ] Connected to proxy1.local (10.0.14.11) port 3128 (#0)
[DEBUG   ] > GET http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dep11/Components-amd64.yml.xz HTTP/1.1
[DEBUG   ] > Host: archive.ubuntu.com
[DEBUG   ] > Accept: */*
[DEBUG   ] > Accept-Encoding: none
[DEBUG   ] > Proxy-Connection: Keep-Alive
[DEBUG   ] > User-Agent: Salt/3004.2 http.query()
[DEBUG   ] >
[DEBUG   ] Mark bundle as not supporting multiuse
[DEBUG   ] < HTTP/1.1 200 OK
[DEBUG   ] < Date: Tue, 18 Apr 2023 13:44:06 GMT
[DEBUG   ] < Server: Apache/2.4.29 (Ubuntu)
[DEBUG   ] < Last-Modified: Tue, 18 Apr 2023 08:24:02 GMT
[DEBUG   ] < ETag: "43018-5f99807af942d"
[DEBUG   ] < Accept-Ranges: bytes
[DEBUG   ] < Content-Length: 274456
[DEBUG   ] < Content-Type: application/x-xz
[DEBUG   ] < Age: 131
[DEBUG   ] < X-Cache: HIT from proxy1.local
[DEBUG   ] < X-Cache-Lookup: HIT from proxy1.local:3128
[DEBUG   ] < Via: 1.1 proxy1.local (squid/4.10)
[DEBUG   ] < Connection: keep-alive
[DEBUG   ] <
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfd in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfd in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfd in position 0: invalid start byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x9e in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x9e in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x9e in position 0: invalid start byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb4 in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb4 in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb4 in position 0: invalid start byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb1 in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb1 in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb1 in position 0: invalid start byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa4 in position 1: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa4 in position 1: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa4 in position 1: invalid start byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xda in position 2: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xda in position 2: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xda in position 2: invalid continuation byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfe in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfe in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfe in position 0: invalid start byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x9e in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x9e in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x9e in position 0: invalid start byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc2 in position 7: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc2 in position 7: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc2 in position 7: invalid continuation byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc1 in position 1: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc1 in position 1: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc1 in position 1: invalid start byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd1 in position 3: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd1 in position 3: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd1 in position 3: invalid continuation byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode bytes in position 2-3: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode bytes in position 2-3: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode bytes in position 2-3: invalid continuation byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x9c in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x9c in position 0: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x9c in position 0: invalid start byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd9 in position 1: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd9 in position 1: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd9 in position 1: invalid continuation byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x88 in position 8: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x88 in position 8: invalid start byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x88 in position 8: invalid start byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode bytes in position 1-2: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode bytes in position 1-2: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode bytes in position 1-2: invalid continuation byte
[ERROR   ] An un-handled exception was caught by salt's global exception handler:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xca in position 2: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xca in position 2: invalid continuation byte
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/curl_httpclient.py", line 497, in _curl_debug
    debug_msg = native_str(debug_msg)
  File "/usr/lib/python3/dist-packages/salt/ext/tornado/escape.py", line 219, in to_unicode
    return value.decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xca in position 2: invalid continuation byte
[DEBUG   ] Connection #0 to host proxy1.local left intact
[INFO    ] File changed:

[INFO    ] Completed state [/tmp/test.download] at time 13:46:12.900403 (duration_in_ms=75.855)
[DEBUG   ] File /var/cache/salt/minion/accumulator/139663626267328 does not exist, no need to cleanup
[DEBUG   ] LazyLoaded state.check_result
[DEBUG   ] LazyLoaded highstate.output
[DEBUG   ] LazyLoaded nested.output
local:
----------
          ID: download_proxy_test
    Function: file.managed
        Name: /tmp/test.download
      Result: True
     Comment: File /tmp/test.download updated
     Started: 13:46:12.824548
    Duration: 75.855 ms
     Changes:
              ----------
              diff:

Summary for local
------------
Succeeded: 1 (changed=1)
Failed:    0
------------
Total states run:     1
Total run time:  75.855 ms

Expected behavior
The file should download without errors.

Screenshots
N/A

Versions Report

salt --versions-report

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

Salt Version:
          Salt: 3004.2

Dependency Versions:
          cffi: Not Installed
      cherrypy: Not Installed
      dateutil: 2.7.3
     docker-py: Not Installed
         gitdb: Not Installed
     gitpython: Not Installed
        Jinja2: 2.10.1
       libgit2: Not Installed
      M2Crypto: Not Installed
          Mako: Not Installed
       msgpack: 0.6.2
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     pycparser: Not Installed
      pycrypto: 2.6.1
  pycryptodome: 3.6.1
        pygit2: Not Installed
        Python: 3.8.10 (default, Nov 14 2022, 12:59:47)
  python-gnupg: 0.4.5
        PyYAML: 5.3.1
         PyZMQ: 18.1.1
         smmap: Not Installed
       timelib: Not Installed
       Tornado: 4.5.3
           ZMQ: 4.3.2

System Versions:
          dist: ubuntu 20.04 focal
        locale: utf-8
       machine: x86_64
       release: 5.4.0-77-generic
        system: Linux
       version: Ubuntu 20.04 focal

Additional context
Add any other context about the problem here.

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[OrangeDog]

Can you intercept and show the response headers that the proxy is returning?
If the proxy is claiming that it's UTF-8 when it's not then that would be where a fix is needed.

[maltris]

Intercepting any traffic and checking wont help here.

A tornado update will. If you go and patch the file /opt/saltstack/salt/lib/python3.10/site-packages/salt/ext/tornado/curl_httpclient.py manually to the latest version from tornado 6.4.0 like this:

Old code:

    def _curl_debug(self, debug_type, debug_msg):
        debug_types = ('I', '<', '>', '<', '>')
        debug_msg = native_str(debug_msg)
        if debug_type == 0:
            curl_log.debug('%s', debug_msg.strip())
        elif debug_type in (1, 2):
            for line in debug_msg.splitlines():
                curl_log.debug('%s %s', debug_types[debug_type], line)
        elif debug_type == 4:
            curl_log.debug('%s %r', debug_types[debug_type], debug_msg)

New code (latest tornado lib):

    def _curl_debug(self, debug_type: int, debug_msg: str) -> None:
        debug_types = ("I", "<", ">", "<", ">")
        if debug_type == 0:
            debug_msg = native_str(debug_msg)
            curl_log.debug("%s", debug_msg.strip())
        elif debug_type in (1, 2):
            debug_msg = native_str(debug_msg)
            for line in debug_msg.splitlines():
                curl_log.debug("%s %s", debug_types[debug_type], line)
        elif debug_type == 4:
            curl_log.debug("%s %r", debug_types[debug_type], debug_msg)

The error disappears after replacing the block. I suppose this is because of different handling on the DEBUGMESSAGE callback from pycurl since version 7.19.5.2: The second argument to a DEBUGFUNCTION callback is now of type bytes on Python 3. Previously the argument was of type str. (Source)

However, in my use-cases, the message did not prevent the function. It was merely an annoying bunch of tracebacks on each saltstate-call.

Tornado lib in salt is scheduled to be updated in 3007.x as I have read in #64305. So from that release on the error should not appear anymore.