Hi!

Trying to run the following command in R fails unless I use the SerialParam:

bplapply(1:6, sqrt, BPPARAM = SerialParam()) -> WORKS

bplapply(1:6, sqrt) -> FAILS (unresponsive)

bplapply(1:6, sqrt, BPPARAM = MulticoreParam(2)) -> FAILS (unresponsive)

bplapply(1:6, sqrt, BPPARAM = MulticoreParam(1)) -> WORKS

Any ideas what to do?

> sessionInfo()
R version 3.5.2 (2018-12-20)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS Mojave 10.14.3

Matrix products: default
BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.5/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] BiocParallel_1.16.6

loaded via a namespace (and not attached):
[1] compiler_3.5.2 snow_0.4-3     parallel_3.5.2 tools_3.5.2    yaml_2.2.0 

These functions communicate via 'ports', and likely ports on your machine are not accessible. It might take some research to identify open ports, and then provide manager.port=... to the constructor.

You might also be interested in the LocalParam() type, available after

BiocManager::install("Bioconductor/BiocParallel", ref="LocalParam")