Error generated by .Internal(nchar) disappears when debugging

Joris Meys <jorismeys <at> gmail.com> writes:

Hi all,

I have a puzzling problem related to nchar. In R 3.2.1, the internal 

nchar

gained an extra argument (see
https://stat.ethz.ch/pipermail/r-announce/2015/000586.html)

I've been testing code using the package copula, and at home I'm still
running R 3.2.0 (I know, I know...). When trying the following code, I 

got

an error:

library(copula)
fgmCopula(0.8)

Error in substr(sc[i], 2, nchar(sc[i]) - 1) :
  4 arguments passed to .Internal(nchar) which requires 3

Cheers
Joris

I'm seeing a similar problem. IIUC, the Windows binary .zip from CRAN of 
any package using base::nchar is affected. Could someone check my answer 
here is correct please : http://stackoverflow.com/a/32959306/403310

Nobody has posted a simple reproducible example here, so it's kind of
hard to say.

I would have guessed that a change to the internal signature of the C
code underlying nchar() wouldn't have any effect on a package that
called the R nchar() function.

When I put together my own example (a tiny package containing a function
calling nchar(), built to .zip using R 3.2.2, installed into R 3.2.0),
it confirmed my guess.

On the other hand, if some package is calling the .Internal function
directly, I'd expect that to break.  Packages shouldn't do that.

So I'd say there's been no evidence posted of a problem in R here,
though there may be problems in some of the packages involved.  I'd
welcome an example that provided some usable evidence.

Duncan Murdoch