rxUse Failure on Windows

[billdenney]

TL;DR: Should we skip the rxUse test on Windows?

When running the rxUse()/rxPkg() tests, there is an error on Windows (ref #29). My initial testing found that the error was here:

rxode2/R/rxode2.R

Line 1338 in 2908fc9

dyn.unload(.cDllFile)

And the error was:

Error in dyn.unload(.cDllFile) : 
  shared object 'C:/Users/BILLDE~1/AppData/Local/Temp/RTMPUC~2/RXUSE-~1/rxm/inst/rx/rxm_mod.dll' was not loaded

I got farther when I modified the line above to be try({dyn.unload(.cDllFile)}), but there was a later error that I couldn't directly identify. I'd be a bit worried to wrap the dyn.unload() in try() in a general sense. The function seems a bit ancillary to the main purpose of rxode2, so I'd lean toward ignoring the error on Windows. And possibly, we could give a warning that the function may not work on Windows for any users.

@mattfidler, What are your thoughts?

[mattfidler]

There is a way to see if a dll is loaded. I will do something here.

[mattfidler]

This is failing with multiple models because it is having a hard time unloading then deleting the temporary directory where the c code is generated.