CMD check error

I have a new package (local use only).  R CMD check fails with a messge I haven't seen before, and I haven't been able to guess the cause.
There are two vignettes, both of which have %\VignetteIndexEntry lines.

Same failure both under R-3.1.1 and R-devel, so it's me and not R.  Linux OS.

Hints anyone?

Terry Therneau

=================================================

tmt% R CMD build dart
* preparing 'dart':
* checking DESCRIPTION meta-information ... OK
* installing the package to build vignettes
* creating vignettes ... OK
* checking for LF line-endings in source and make files
* checking for empty or unneeded directories
* looking to see if a 'data/datalist' file should be added
* building 'dart_1.0-2.tar.gz'

tmt% R CMD check dart*gz
...
Installation failed.
See '/people/biostat2/therneau/consult/bsi/dart.Rcheck ...

tmt% more dart.Rcheck/00install.out
...
** installing vignettes
Warning in file(con, "w") :
   cannot open file '/people/biostat2/therneau/consult/bsi/dart.Rcheck/dart/doc/
index.html': No such file or directory
Error in file(con, "w") : cannot open the connection
ERROR: installing vignettes failed
* removing '/people/biostat2/therneau/consult/bsi/dart.Rcheck/dart'