error starting R-devel with --arch ppc -- "an unusual circumstance has arisen"

When I try and start R-devel as follows:

R --vanilla --arch ppc

I see this, over and over again, ^C does not interrupt it and I have
to close the terminal window:

Error in paste0(prefix, conditionMessage(e), "\n") :

not a BUILTIN function
In addition: Warning message:
An unusual circumstance has arisen in the nesting of readline input.
Please report using bug.report()

Error in paste0(prefix, conditionMessage(e), "\n") :

not a BUILTIN function
In addition: Warning message:
An unusual circumstance has arisen in the nesting of readline input.
Please report using bug.report()

I can't get to sessionInfo() but here is sessionInfo() of the same R
invoked with no --arch argument:

R Under development (unstable) (2011-12-14 r57899)
Platform: i386-apple-darwin9.8.0/i386 (32-bit)

locale:
[1] C

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


This seems to be related to the issue I reported here previously:
https://stat.ethz.ch/pipermail/r-devel/2011-December/062793.html


Thanks,
Dan