This came up in the support meetings. Probably we should have a
- pre-hook (at the start of EESSI initialization)
- post-hook (at the end of EESSI initialization)
That each allow sourcing of a script from within the host_injections prefix. I.e. each hook should do something like 'check if script exist, if so, source'.
This would allow sites to modify the initialization of EESSI, e.g. on Olivia the PYTHONSTARTUP variable needs to be unset before loading EESSI.