In case anyone's still interested in this, I found a pacman.conf option
called NoExtract, which lets you tell pacman not to overwrite certain files
and directories in the filesystem. So you could add the following line to
/etc/pacman.conf:
NoExtract = /usr/bin/python
which would prevent pacman from overwriting the custom /usr/bin/python
script. Here is the most recent version of the /usr/bin/python script:
#!/usr/bin/env bash
test "$PYTHON" != "python2" -a "$PYTHON" != "python3" && unset PYTHON
exec /usr/bin/"${PYTHON:-python3}" "$@"
This version does some input checking to make sure the only valid options
for the PYTHON environment variable are "python2" or "python3".
Ben
