python set by -P flag is not used/overwritten (in sixdb.sh and run_six.sh)

[JoschD]

calling sixdb.sh with the -P flag to set a python does this, but overrides it immediately after.

$ /afs/cern.ch/project/sixtrack/SixDesk_utilities/pro/utilities/bash/sixdb.sh -P python3 . load_dir
Wed 14/10/20 19:59:47  sixdb.sh Setting python to python3 in PATH env var
Wed 14/10/20 19:59:47  sixdb.sh Python set to: /usr/bin/python - version: Python 2.7.5 

This is especially bad as sixdb (python in utilities/externals/SixDeskDB/) requires now python3 (it doesn't check for it yet, but the code raises a syntax error in python .) see SixTrack/SixDeskDB#37
making sixdb.sh unusable at the moment.

[JoschD]

Related:
/afs/cern.ch/project/sixtrack/SixDesk_utilities/pro/utilities/bash/run_six.sh -a -P /afs/cern.ch/eng/sl/lintrack/miniconda2/bin/python

Does not seem to work either. Instead, the python on the system or currently sourced environment is used.

e.g. when python is not available (e.g. Ubuntu 20.04)

run_six.sh Python set to:  - version: /afs/cern.ch/project/sixtrack/SixDesk_utilities/pro/utilities/bash/dot_profile: line 806: python: command not found
(...)
 python version too new: found
 please use at most 3 (excluded)

or in a python3 sourced environment

run_six.sh Python set to: /home/jdilly/Software/venvs/pylhc_as_external/bin/python - version: Python 3.7.8
(...)
python version too new: 3.7.8
please use at most 3 (excluded)

Edit: I misunderstood the -P. It only wants the path to the bin directory.

$ /afs/cern.ch/project/sixtrack/SixDesk_utilities/pro/utilities/bash/run_six.sh -a -P /afs/cern.ch/eng/sl/lintrack/miniconda2/bin/
Python set to: /afs/cern.ch/eng/sl/lintrack/miniconda2/bin/python - version: Python 2.7.16 :: Anaconda, Inc.
python version too new: Inc.
please use at most 3 (excluded)