Read from shell environment variable if exists

[casassg]

This solves an issue when hermit is activated by non interactive bash scripts (as it happens in Slurm for example) and when the /etc/passwd is not populated as its dynamically set by some system daemon (example: OS Login in GCP).

This leads to the following error:

fatal:hermit: /etc/passwd file entry for "gerardc_squareup_com" is missing

SHELL should be populated automatically by login on all unix systems (which gets set by reading from passwd database or by checking the default). So we can just use it to set it.

[alecthomas]

I don't think this is going to solve your problem. I believe that error is a result of calling user.Current(), and we use that in many other locations in Hermit.

[casassg]

I don't think this is going to solve your problem. I believe that error is a result of calling user.Current(), and we use that in many other locations in Hermit.

nope, user.Current() is correct (see the trace printing gerardc_squareup_com which is indeed the correct user).

[alecthomas]

Can you put this below the ppid check please.

[casassg]

sure thing!

[casassg]

@alecthomas could this be merged and deployed?