rstudioapi::restartSession() doesn't unload packages

[burchill]

I just noticed that when I call rstudioapi::restartSession() in the console, the packages I had loaded previously are still there. This differs from the behavior of clicking on Session > Restart R, which doesn't have the following issue.

I inputted the commands below, expecting R to throw an error when select was called for the second time, but it did not and worked the same both times.

library(dplyr)
select(data.frame(x=1,y=1), y)
rstudioapi::restartSession()
select(data.frame(x=1,y=1), y)

Additionally, after restarting the session, the follow message appeared:

Warning message:
package ‘dplyr’ was built under R version 3.3.2 

I'm using R version 3.3.1 (2016-06-21) and RStudio v. 1.1.456

[MilesMcBain]

I've just reproduced this in the current R release. I think this is an important issue because the misconception that this creates a completely fresh session could lead to unexpected reproducibility failures.

Edit: I've just discovered that restartSession() preserves the environment:

> a <- 1
> rstudioapi::restartSession()

Restarting R session...

> a
[1] 1
> 

This is completely unexpected to me, to the point where I am no longer sure what the usecase of this function is. Is this function named in a misleading way?

> sessionInfo()
R version 3.5.2 (2018-12-20)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Debian GNU/Linux 9 (stretch)

Matrix products: default
BLAS: /usr/lib/openblas-base/libblas.so.3
LAPACK: /usr/lib/libopenblasp-r0.2.19.so

locale:
 [1] LC_CTYPE=en_AU.UTF-8       LC_NUMERIC=C               LC_TIME=en_AU.UTF-8       
 [4] LC_COLLATE=en_AU.UTF-8     LC_MONETARY=en_AU.UTF-8    LC_MESSAGES=en_AU.UTF-8   
 [7] LC_PAPER=en_AU.UTF-8       LC_NAME=C                  LC_ADDRESS=C              
[10] LC_TELEPHONE=C             LC_MEASUREMENT=en_AU.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] rstudioapi_0.9.0

loaded via a namespace (and not attached):
[1] compiler_3.5.2 tools_3.5.2    packrat_0.5.0 

[mlell]

As of RStudio 2024.09.0 & rstudioapi 0.16.0 (my versions, probably earlier), restartSession(clean = TRUE) shows the intended behaviour. (See rstudio/rstudio#2841)

library(dplyr)
select(data.frame(x=1,y=1), y)
##    y
## 1 1
rstudioapi::restartSession()

## Restarting R session...

select(data.frame(x=1,y=1), y)
##   y
## 1 1
 
rstudioapi::restartSession(clean = TRUE)
## Restarting R session...
select(data.frame(x=1,y=1), y)
## Error in select(data.frame(x = 1, y = 1), y) : 
##   could not find function "select"