[xxyzz]

But the same code runs fine on Fedora's python.

import subprocess

r = subprocess.run(["python3", "-m", "pip", "--version"], check=True, text=True, capture_output=True)

this would fail in calibre-debug,

`r.stderr`:

Could not find platform independent libraries <prefix>\n
Could not find platform dependent libraries <exec_prefix>\n
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]\n
Python path configuration:\n  
PYTHONHOME = (not set)\n  
PYTHONPATH = (not set)\n  
program name = 'python3'\n  
isolated = 0\n  
environment = 1\n  
user site = 1\n  
import site = 1\n 
sys._base_executable = '/usr/bin/python3'\n  
sys.base_prefix = '/tmp/t/python-n51y8gtd'\n  
sys.base_exec_prefix = '/tmp/t/python-n51y8gtd'\n  
sys.platlibdir = 'lib'\n  
sys.executable = '/usr/bin/python3'\n  
sys.prefix = '/tmp/t/python-n51y8gtd'\n  
sys.exec_prefix = '/tmp/t/python-n51y8gtd'\n  
sys.path = [\n
    '/tmp/t/python-n51y8gtd/lib/python310.zip',\n
    '/tmp/t/python-n51y8gtd/lib/python3.10',\n
    '/tmp/t/python-n51y8gtd/lib/lib-dynload',\n
]\n
Fatal Python error: init_fs_encoding: failed to get the Python codec of the filesystem encoding\n
Python runtime state: core initialized\n
ModuleNotFoundError: No module named 'encodings'\n\n

Current thread 0x00007f824f149740 (most recent call first):\n
<no Python frame>\n"