Ensure reproducible if using model cache

[gowerc]

Closes #469

FYI @luwidmer

[luwidmer]

@gowerc doesn't .Random.seed always exist? At least I get

Restarting R session...

> exists(".Random.seed")
[1] TRUE
> ls()
character(0)
> .Random.seed <<- .Random.seed
> ls()
character(0)
> exists(".Random.seed")
[1] TRUE

[gravesti]

I think it doesn't necessarily exist. eg if I start a new R session from the terminal

gravesti$ R

R version 4.4.1 (2024-06-14) -- "Race for Your Life"
Copyright (C) 2024 The R Foundation for Statistical Computing
Platform: aarch64-apple-darwin20
... snip ...

> .Random.seed
Error: object '.Random.seed' not found
> rnorm(1)
[1] -0.6881252
> .Random.seed
  [1]       10403           2 -1831660992  -462780898 -1349857047   996995611
  [7]   676991530   594638156 -1127753969  1257593413  1702644732  1213026898
 [13]  -333959219  -261150329 -1072259986   635315272  1119354443    93778857
 [19]   864664312   193269286  -542546111 -1416680237  1130410114   418352820
 [25]   -98325961  -999378643 -1509490108  1850580842   640379861   544927087

[luwidmer]

Yup, turns out I didn't have a completely new R session even after restarting! Thank you for testing @gowerc & @gravesti ! IMO the on.exit() solution (when .Random.seed exists) would be a pretty robust one.

[gowerc]

Yup, turns out I didn't have a completely new R session even after restarting! Thank you for testing @gowerc !

In fairness I had no idea it wasn't created on new R sessions until all the CICD tests failed unexpectedly 😓

[gowerc]

@gravesti - Ok should be good for review now. I adapted the code you shared a little bit as I realised when the processx update goes on CRAN the rm statement might throw an error as the seed may not have ever been created or updated so we need to conditionally check if it exists to handle both the old and the new/upcoming behaviours.