Closed
Description
Currently the parallel loop will hang for the following code snippets
from math import sqrt
from joblib import Parallel, delayed
Parallel(n_jobs=2)(delayed(sqrt)(i) for i in range(0))
or even just
Parallel(n_jobs=2)([])
I'm not too familiar with the internals of the parallel loop, but it seems to be because we are requesting a parallel loop with an empty iterable (it works fine for n_jobs=1, i.e. a flat loop). Up until joblib==0.9.2 this would return an empty list.