Symptom was:
> # python3 ./examples/capture.py output.txt asciinema rec -c 'timeout 3 htop' output.cast
> Traceback (most recent call last):
>   File "[..]/examples/capture.py", line 39, in <module>
>     data = os.read(master_fd, 1024)
> OSError: [Errno 5] Input/output error
>
> # python3 --version
> Python 3.10.13

.. to reduce nesting to simplify the structure.

Symptom was:
> # python3 ./examples/capture.py output.txt asciinema rec -c 'timeout 3 htop' output.cast
> Traceback (most recent call last):
>   File "/usr/lib/python-exec/python3.10/asciinema", line 8, in <module>
>     sys.exit(main())
>   File "/usr/lib/python3.10/site-packages/asciinema/__main__.py", line 61, in main
>     cfg = config.load()
>   File "/usr/lib/python3.10/site-packages/asciinema/config.py", line 226, in load
>     config = Config(get_config_home(env), env)
>   File "/usr/lib/python3.10/site-packages/asciinema/config.py", line 216, in get_config_home
>     raise Exception(
> Exception: need $HOME or $XDG_CONFIG_HOME or $ASCIINEMA_CONFIG_HOME