Make posix shell configurable in distributed

[vchuravy]

Just encountered a system where sh -l doesn't work.

julia/stdlib/Distributed/src/managers.jl

Line 282 in e3adc39

remotecmd = shell_escape_posixly(`sh -l -c $cmds`)

[mgkuhn]

Option -l (act like a login shell) may be a bashism, at least it is not in the POSIX spec for sh.

[mgkuhn]

As far as I can see, all -l does is to cause bash/dash/zsh to make it a so-called “login shell”, which in turn just means it will read and execute commands from /etc/profile and ~/.profile.

[mgkuhn]

@vchuravy What sh on what OS distribution/version was it that complained about -l, just out of curiosity?

[vchuravy]

I think Centos 7 or so and the problem was that sh -l was then running bash scripts.

[mgkuhn]

@vchuravy Did I understand you right that sh -l did actually work (as in: it executed option -l as intended by loading a startup file), but your problem was that there was some bashism in your /etc/profile or ~/.profile that then caused an error from the non-bash shell that sh linked to (e.g., dash)? What does ls -ld /bin/sh show? What was the line that caused an error?

We have arguably a slightly broken promise in that shell=:posix uses two command-line options that are not actually required to be supported by the POSIX standard, namely sh -l and cd --, and we could work around that if that is really a problem in practice. But it sounds like that may not be your actual problem, and fixing your ~/.profile may be the actual solution, e.g. by wrapping bashisms there into a test for bash, such as if [ -n "$BASH"].