forkpty DeprecationWarning in pexpect

[javierggt]

I have been tracking the occurrence of the forkpty warning in Ska3 regression testing. One occurrence (in agasc) can be traced back to pexpect using ptyprocess which in turn calls forkpty.

You can reproduce it with the following:

import warnings
import ska_shell
import numexpr

warnings.filterwarnings("always", category=DeprecationWarning)
ska_shell.run_shell("ls", shell="bash", importenv=None, env=None, getenv=False)

# ska_shell.shell._setup_bash_shell(None)

This warning was introduced in python/cpython#100228 (adding the link to reflect the noise to the source, just for feedback). Funny enough, one of the links back to this issue is from Marie/Sherpa.

[javierggt]

Note that, in this script, you do not get the warning if you comment out the numexpr import. Who knows? Maybe they also fork somewhere.