[R] Error: STRING_ELT() can only be applied to a 'character vector', not a 'builtin'

[Prof Brian Ripley]

I suspect you have a protection problem.  The specific message you quote 
indicates that STRING_ELT is being called on an object of inappropriate 
type: but it is quite likely that it is being called on uninitialized 
memory as the intended object has been garbage-collected.  Messages from a 
corrupted R session do not always make sense: see the debugging info in 
`Writing R Extensions' and especially the use of gctorture and valgrind.

Followups to R-devel, please: this looks very like a programming issue.

On Tue, 17 Oct 2006, Brahm, David wrote:

> I have a daily job that attaches hundreds of pseudo-packages containing
> data as promise objects (DDP's, ref: g.data package), and plots the
> results to a multi-page pdf device.  Sometimes it fails.  Under R-2.2.1
> it just gave segfaults.  Under R-2.3.1 it gave this error message:
>
>   *** caught segfault ***
>  address (nil), cause 'memory not mapped'
>  Traceback:
>   1: load(system.file("data", paste(i, "RData", sep = "."), package =
> pkg), env)
>   2: g.data.load("tm.time", "hist.20051012")
>   3: g.inorder(93500, tm.time, 160000)
>  aborting ...
>  Segmentation fault
>
> Under R-2.4.0, it now gives this message:
>
>  Error: STRING_ELT() can only be applied to a 'character vector', not a
> 'builtin'
>
> (which appears to be generated inside main/memory.c).
>
> I'm sorry I can't give a reproducible example, because it seems to
> happen randomly, and at different points in the process.  So this is
> just a shot in the dark -- does anybody recognize this behavior?  TIA.
>
> -- David Brahm (brahm at alum.mit.edu)
>
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> and provide commented, minimal, self-contained, reproducible code.
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595