Terra tempdir cannot handle "~"

[ailich]

You can set a tempdir in terraOptions that contains a "~" and it is considered valid (and is valid for other functions such as writeRaster); however this will lead to an error later on when the computer attempts to write temp files there. To avoid confusion perhaps have a call to path.expand internally as this solves the issue or throw an error saying the path cannot be used.

library(terra)
#> Warning: package 'terra' was built under R version 4.3.1
#> terra 1.7.38

if(!dir.exists("~/temp")){
  dir.create("~/temp")
}

terraOptions(tempdir=("~/temp"))

r<- rast(matrix(nrow = 10000, ncol=10000))
set.seed(5)
values(r)<- rnorm(ncell(r))

terrain(r)
#> Error: [terrain] path does not exist


terraOptions(tempdir=(path.expand("~/temp")))
terrain(r)
#> |---------|---------|---------|---------|=========================================                                          
#> class       : SpatRaster 
#> dimensions  : 10000, 10000, 1  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> extent      : 0, 10000, 0, 10000  (xmin, xmax, ymin, ymax)
#> coord. ref. :  
#> source      : spat_4DTcZdBbRm1vP2J_24864.tif 
#> name        :        slope 
#> min value   :  0.003808846 
#> max value   : 69.063812256

^{Created on 2023-06-21 with reprex v2.0.2}

[mdsumner]

it's a gdal thing it doesn't normalize the tilde but will create a directory of that name

[rhijmans]

Thanks; that was already done for filename arguments, but not for the tempdir.