Help with "Error in rethrow_call"

[rempsyc]

I was redirected here from an error with the webshot package linked to processx: wch/webshot#97

After installing and loading:

install.packages("webshot")
webshot::install_phantomjs()
library(webshot)

I run:

example(webshot)

Or the examples in the readme.md:

webshot("https://www.r-project.org/", "r.png")

And I consistently get:

Error in rethrow_call(c_processx_exec, command, c(command, args), stdin,  : 
  Command 'C:/Users/username/Documents/R/win-library/3.6/processx/bin/x64/supervisor.exe' not found @win/processx.c:983 (processx_exec)
Type .Last.error.trace to see where the error occured

I was told to try this rather simple processx command:

> process$new("dir", "hello", supervise = TRUE)

Which outputs a similar error.

Error in rethrow_call(c_processx_exec, command, c(command, args), stdin,  : 
  Command 'dir' not found @win/processx.c:994 (processx_exec)
Type .Last.error.trace to see where the error occured

> .Last.error.trace

 Stack trace:

 1. process$new("dir", "hello", supervise = TRUE)
 2. .subset2(public_bind_env, "initialize")(...)
 3. processx:::process_initialize(self, private, command, args, stdin,  ...
 4. rethrow_call(c_processx_exec, command, c(command, args), stdin,  ...

 x Command 'dir' not found @win/processx.c:994 (processx_exec) 

I reinstalled processx in a new R session, but same error. So I manually uninstalled from RStudio and reinstalled again, but same thing.

I wonder whether it could be due to my username having spaces and accents (though I cannot change it). I know it has given me some trouble with other packages in the past.

[gaborcsardi]

My guess is that it is because of the accents indeed. Maybe you could map a windows drive, e.g. H: to your home directory with the subst command as a workaround.

[rempsyc]

How would I go about doing that?

[gaborcsardi]

https://www.google.com/search?q=windows+subst :)

[rempsyc]

I mean I did create a virtual directory H: pointing to my home directory with the subst command. My question is rather, how can I tell processx in R to use H: rather than C:/ ? Because even after doing that I still experience the same error.

[gaborcsardi]

You can set your library path to H: and install your packages there. I don't know if you need to reinstall the packages or just point to them through H:.

(I did not test this, hopefully it works.)

[rempsyc]

Ok got you. I did uninstall processx then reinstalled in "H:/Documents/R/win-library/3.6", still same result. I must say I had already tried installing in the common directory before: "C:/Program Files/R/R-3.6.1/library" with same result.

[gaborcsardi]

I am sorry for the question, but are you are you sure that you are loading the package from that directory? It is easy to mix them up if you have multiple directories.

[rempsyc]

No, that's a good question. I had only assumed I was loading from the correct directory since I always uninstalled first. But no luck when specifying from where to load with lib.loc:

> library("processx", lib.loc="H:/Documents/R/win-library/3.6")
Warning message:
package ‘processx’ was built under R version 3.6.3 

> process$new("dir", "hello", supervise = TRUE)
Error in rethrow_call(c_processx_exec, command, c(command, args), stdin,  : 
  Command 'dir' not found @win/processx.c:994 (processx_exec)
Type .Last.error.trace to see where the error occured

[gaborcsardi]

OK, this is a bug, anyway, let me try to fix it.

[rempsyc]

Do you think it might be due to having R version 3.6.1 while processx was built under 3.6.3? Do you want me to install latest version and test again?

[gaborcsardi]

No, that is very unlikely.

[gaborcsardi]

@rempsyc Which non ASCII character(s) do you have in your path?

[rempsyc]

French accents, "é", e.g, Sébastien Gagné

[gaborcsardi]

Which version of processx is this? What is your system locale? E.g. the output of

library(processx)
sessionInfo()

would be good.

[rempsyc]

> library(processx)
Warning message:
package ‘processx’ was built under R version 3.6.3

> sessionInfo()
R version 3.6.1 (2019-07-05)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18362)

Matrix products: default

locale:
[1] LC_COLLATE=English_Canada.1252  LC_CTYPE=English_Canada.1252   
[3] LC_MONETARY=English_Canada.1252 LC_NUMERIC=C                   
[5] LC_TIME=English_Canada.1252    

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

other attached packages:
[1] processx_3.4.3

loaded via a namespace (and not attached):
[1] compiler_3.6.1 tools_3.6.1    ps_1.3.3      

[gaborcsardi]

R 3.6.x is not great for non-ASCII paths, unfortunately. There is a good chance that your problem is fixed in R 4.0.x, which has:

• file.path() has some support for file paths not in the session encoding, e.g. with UTF-8 inputs in a non-UTF-8 locale the output is marked as UTF-8.
• Most functions with file-path inputs will give an explicit error if a file-path input in a marked encoding cannot be translated (to the native encoding or in some cases on Windows to UTF-8), rather than translate to a different file path using escapes. Some (such as dir.exists(), file.exists(), file.access(), file.info(), list.files(), normalizePath() and path.expand()) treat this like any other non-existent file, often with a warning.

[rempsyc]

Great! I will try that and come back to you.

[rempsyc]

Ok, just updated R and RStudio. Same error (edit: for process$new("dir", "hello", supervise = TRUE)). Could it simply be that dir is also not a Windows executable like you pointed out in the other thread? Do you have any other command to make me try?

[rempsyc]

Actually, I just retried

library(webshot)
webshot("https://www.r-project.org/", "r.png")

And now it works! I guess because of the R update. And as for the dir command, maybe it simply didn't work because it's not a Windows executable as you said!