compose: Docker Desktop for Windows Stable 2.2.0.0 - docker-compose exec Unicode errors

• I have tried with the latest version of my channel (Stable or Edge)
• I have uploaded Diagnostics
• Diagnostics ID:

Expected behavior

docker-compose.exe behaves as it did in Docker Desktop for Windows 2.1.0.5.

Actual behavior

If terminal code page is UTF-8, docker-compose exec fails with LookupError: unknown encoding: cp65001 If .env file contains any entries, docker-compose exec fails with TypeError: environment can only contain strings

Information

• Windows Version: Windows 10 Pro, build 18363.592
• Docker Desktop Version: 2.2.0.0
• Are you running inside a virtualized Windows e.g. on a cloud server or on a mac VM: No

The bundled docker-compose.exe appears to have been compiled using Python 2.7 and an older version of python-dotenv.

The issue can be worked around by installing docker-compose via pip and Python 3

Steps to reproduce the behavior

1. Add docker-compose.yml:

    version: "3"
    services:
      test:
        image: ubuntu
        command: tail -f /dev/null
   

2. Add .env:

    A=
   

3. In powershell, run:

    $OutputEncoding = `
      [Console]::OutputEncoding = `
      [Console]::InputEncoding = [Text.Encoding]::UTF8
    chcp.com 65001
    docker-compose down
    docker-compose up -d test
    docker-compose exec test echo 1
   

4. Observe unexpected error:

    Traceback (most recent call last):
      File "logging\__init__.py", line 879, in emit
      File "site-packages\colorama\ansitowin32.py", line 41, in write
      File "site-packages\colorama\ansitowin32.py", line 162, in write
      File "site-packages\colorama\ansitowin32.py", line 187, in write_and_convert
      File "site-packages\colorama\ansitowin32.py", line 195, in write_plain_text
    LookupError: unknown encoding: cp65001
    Logged from file main.py, line 78
   

5. Switch codepage to Windows 1252 and try again:

    $OutputEncoding = `
      [Console]::OutputEncoding = `
      [Console]::InputEncoding = [Text.Encoding]::GetEncoding(1252)
    chcp 1252
    docker-compose exec test echo 1
   

6. Observe error:

    Traceback (most recent call last):
      File "docker-compose", line 6, in <module>
      File "compose\cli\main.py", line 72, in main
      File "compose\cli\main.py", line 128, in perform_command
      File "compose\cli\main.py", line 491, in exec_command
      File "compose\cli\main.py", line 1469, in call_docker
      File "subprocess.py", line 172, in call
      File "subprocess.py", line 394, in __init__
      File "subprocess.py", line 644, in _execute_child
    TypeError: environment can only contain strings
    [8940] Failed to execute script docker-compose
   

7. Remove .env and try again:

    rm .env
    docker-compose down
    docker-compose up -d test
    docker-compose exec test echo 1
   

8. Observe expected output: 1