mpiexec deprecation warning

[miguelbiron]

Caught this while running the pkg tests

### Starting test_checkpoint.jl
┌ Info: Neither traces, disk, nor online recorders included. 
│    You may not have access to your samples (unless you are using a custom recorder, or maybe you just want log(Z)).
└    To add recorders, use e.g. pigeons(target = ..., record = [traces; record_default()])
────────────────────────────────────────────────────────────────────────────
  scans        Λ        time(s)    allc(B)  log(Z₁/Z₀)   min(α)     mean(α) 
────────── ────────── ────────── ────────── ────────── ────────── ──────────
        2      0.609   0.000136   1.14e+04      -1.68      0.705      0.932 
        4       1.28   8.69e-05    1.8e+04      -1.86      0.527      0.858 
        8       1.39   0.000116   3.28e+04      -2.29      0.458      0.845 
       16       1.55   0.000198   5.69e+04      -2.27      0.646      0.828 
       32       1.22   0.000283   7.48e+04      -2.27      0.727      0.865 
       64        1.1   0.000463   7.91e+04      -2.09      0.738      0.877 
      128        1.1    0.00105   7.89e+04      -2.36      0.814      0.878 
      256       1.17    0.00113   7.79e+04      -2.23      0.846      0.869 
      512       1.08    0.00107   7.79e+04      -2.33      0.847       0.88 
 1.02e+03       1.14    0.00172   7.79e+04       -2.3      0.855      0.874 
────────────────────────────────────────────────────────────────────────────
┌ Info: Neither traces, disk, nor online recorders included. 
│    You may not have access to your samples (unless you are using a custom recorder, or maybe you just want log(Z)).
└    To add recorders, use e.g. pigeons(target = ..., record = [traces; record_default()])
┌ Warning: mpiexec() is deprecated, use the non-do-block form
│   caller = ip:0x0
└ @ Core :-1

[miguelbiron]

It's coming directly from JLLWrappers.

[miguelbiron]

seems related to this warning about thread safety https://docs.julialang.org/en/v1/base/base/#Base.withenv

[miguelbiron]

Ok so basically the new approach seems to be

run(`$(mpiexec()) -n 3 echo hello world`)

versus the old do-block approach

mpiexec() do cmd
    run(`$cmd -n 3 echo hello world`)
end

This deprecation was until recently not documented by MPI.jl, but now there is a brief mention in the docs.