[R-sig-Debian] possible Sweave problem in rdevel build on Debian 6.0.8?

[Skye Bender-deMoll]

Dear R-sig-debian,

As of last night, we are running into a build failure when trying to
compile the development version of R from the svn repository, Revision:
64090:

./configure && make -j4 distclean && ./configure && make -j4

[lots of normal compile output not shown...]

building/updating vignettes for package 'utils' ...
processing 'Sweave.Rnw'
Error: running Sweave on vignette
'/net/home/rpackagebuilder/src/R.trunk/src/library/utils/vignettes/Sweave.Rnw' 

failed with message:
<text>:1:1: unexpected '|'
1: |
      ^
Execution halted
make[1]: *** [vignettes-lattice] Error 1
make[1]: Leaving directory
`/net/home/rpackagebuilder/src/R.trunk/src/library'
make: *** [vignettes] Error 2


The same vignette compiles without error on the same machine using the
stable release version of R.  Does anyone have suggestions on how I
might debug this further to determine if this is an issue with Sweave,
the vignette, or our system configuration?

thanks for your help,
   -skye