Set a default for NCORES

[jeroen]

I see a bunch of warnings when configuring:

-- Build files have been written to: /tmp/RtmpjkUDAr/file1c4d6c6cb7/nloptr/src/nlopt-build
make: the '-j' option requires a positive integer argument
Usage: make [options] [target] ...

The issue is that when NCORES Is unset, the argument is incomplete. This sets a default if NCORES is unset to 1.

[eddelbuettel]

Can you move the fixing logic higher up? The script starts with

: ${R_HOME=$(R RHOME)}
RSCRIPT_BIN=${R_HOME}/bin/Rscript
NCORES=`${RSCRIPT_BIN} -e "cat(min(2, parallel::detectCores(logical = FALSE)))"`

Why does that not work in your settings?

[jeroen]

Ah good point. It seems to return NA on WebAssembly.

[jeroen]

OK so the real problem is we are not accounting for the case where parallel::detectCores(logical = FALSE)) returns NA.

[eddelbuettel]

Can you bubble that up to webr / wasm ?

[jeroen]

The source of detectCores() show that NA is the default return value in cases that it fails to guess. So it would probably be appropriate to deal with that outcome when you call it here. But it's no biggy.