"No suitable spell-checker program found"

[bersbersbers]

Is your feature request related to a problem? Please describe.
Running devtools::check(incoming = T, quiet = T) simply returns 0 errors ✔ | 0 warnings ✔ | 0 notes ✔ although the package I am checking has numerous problems.

The reason can (only) be seen with devtools::check(incoming = T, quiet = F):

...
─  checking CRAN incoming feasibility ...Error in aspell(files, filter = list("dcf", ignore = ignore), control = control,  : 
     No suitable spell-checker program found
   Execution halted
   
── R CMD check results ──...
Duration: 1.3s

0 errors ✔ | 0 warnings ✔ | 0 notes ✔
> 

Describe the solution you'd like
Indicate that checks have not been completed, maybe by adding an error.

[bersbersbers]

Just adding a few bits of information here:

• R -q -e "utils::aspell('run.R')" works fine, and so does ... "utils::aspell(NULL)"
• aspell is not installed globally as far as I can see:

$ aspell
If 'aspell' is not a typo you can use command-not-found to lookup the package that contains it, like this:
    cnf aspell

• utils:::aspell_find_program(NULL) returns

           hunspell 
"/usr/bin/hunspell" 

[bersbersbers]

The second problem is this:

R CMD check uses utils::aspell(program = "aspell"):
https://github.com/wch/r-source/blob/b6b0a445f44b51507281ef48e032b18606c25ebc/src/library/tools/R/QC.R#L7102-L7108

But devtools checks for utils::aspell(program = NULL):

devtools/R/check.R

Lines 241 to 246 in d5901f8

	aspell_env_var <- function() {
	tryCatch({
	utils::aspell(NULL)
	c("_R_CHECK_CRAN_INCOMING_USE_ASPELL_" = "TRUE")
	}, error = function(e) character())
	}

In my case,

> utils:::aspell_find_program(NULL)
           hunspell 
"/usr/bin/hunspell" 
> utils:::aspell_find_program("aspell")
<NA> 
  NA 

So utils::aspell("run.R", program = NULL) works, but utils::aspell("run.R", program = "aspell") does not.

So in summary, there is two issues:

1. devtools should (also?) check !is.na(utils:::aspell_find_program("aspell"))
2. If _R_CHECK_CRAN_INCOMING_USE_ASPELL_ is set (for whatever reason - even manually by the user) R CMD check fails due to aspell failing, this should be reported as an error.

[hadley]

PR fixes 1; rcmdcheck issue tracks 2.