R Under development (unstable) (2025-02-23 r87804 ucrt) -- "Unsuffered Consequences"
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> library("R.utils")
Loading required package: R.oo
Loading required package: R.methodsS3
R.methodsS3 v1.8.2 (2022-06-13 22:00:14 UTC) successfully loaded. See ?R.methodsS3 for help.
R.oo v1.27.0 (2024-11-01 18:00:02 UTC) successfully loaded. See ?R.oo for help.

Attaching package: 'R.oo'

The following object is masked from 'package:R.methodsS3':

    throw

The following objects are masked from 'package:methods':

    getClasses, getMethods

The following objects are masked from 'package:base':

    attach, detach, load, save

R.utils v2.13.0 successfully loaded. See ?R.utils for help.

Attaching package: 'R.utils'

The following object is masked from 'package:utils':

    timestamp

The following objects are masked from 'package:base':

    cat, commandArgs, getOption, isOpen, nullfile, parse, use, warnings

> 
> # Use with one package
> use("tools", how="load")
> 
> # Use with one package
> use("tools")
> 
> # Use with multiple packages
> use(c("tools", "graphics"))
> use("tools, graphics")
> use(c("tools, graphics", "grDevices"))
> 
> # Use with version constraint
> use("tools", version="(>= 2.5.0)")
> use("tools (>= 2.5.0)")
> 
> # Use with multiple packages and version constraints
> use(c("tools", "graphics"), version=c("(>= 2.5.0)", "(>= 2.5.0)"))
> use("tools, graphics", version="(>= 2.5.0), (>= 2.5.0)")
> use("tools (>= 2.5.0), graphics (>= 2.5.0)")
> 
> # Exception should be visible
> tryCatch({
+   use("NonExistingPackage", install=FALSE)
+ }, error = function(ex) {
+   print(ex)
+ })
[2025-02-24 21:22:25.707791] Exception: Failed to attach package:NonExistingPackage

  at #06. use.default("NonExistingPackage", install = FALSE)
          - use.default() is in environment 'R.utils'

  at #05. use("NonExistingPackage", install = FALSE)
          - use() is in environment 'R.utils'

> 
> proc.time()
   user  system elapsed 
   0.26    0.04    0.29