Setting env. variables like JULIA_NUM_THREADS for remote workers

[oschulz]

There currently doesn't seem to be a method to control/set/forward environment variables for remote workers, e.g. workers started with

addprocs([host1, ...])

One important variable that users may want to set is JULIA_NUM_THREADS. But in more complex real-world situation, one may also need to set (resp. forward) things like PATH, LD_LIBRARY_PATH (for custom software packages) and other (site- and application-dependent) variables.

Maybe addprocs could get an env kwarg or so?

[ViralBShah]

cc @amitmurthy

[xgdgsc]

Also hoping this could be added so I only have one JULIA_DEPOT_PATH JULIA_PROJECT shared on nfs between nodes. For now I edit ~/.bashrc and add export JULIA_DEPOT_PATH=... on nodes. I' d like to add envs to machine file.

[mgkuhn]

Julia 1.6 added a new env=["JULIA_DEPOT_PATH"=>"/depot", ...] keyword argument to Distributed.addprocs that solves this issue.