Installed maxima can't find maxima-index.lisp

I have a problem with latest git head on windows, using both gcl and 
sbcl.  The installed maxima can't find maxima-index.lisp.  All is OK 
running maxima-local in the build tree.  I don't have time to 
investigate further tonight.

The error message is:

WARNING: Maxima is unable to set up the help system.
(Details: CL-INFO::LOAD-PRIMARY-INDEX: Couldn't load
"c:/maxima/info/./maxima-index.lisp":
                                        file does not exist.)

Of note:
  - maxima is configured with --prefix=c:/maxima
  - maxima-index.lisp is installed into c:/maxima/share/info
  - maxima-infodir, according to the installed maxima, is c:/maxima/info

### Installed maxima ###
(%i2) :lisp (print-directories)
maxima-prefix=c:/maxima
maxima-imagesdir=c:/maxima/lib/maxima/5.31post/binary-sbcl
maxima-sharedir=c:/maxima/share/maxima/5.31post/share
maxima-srcdir=c:/maxima/share/maxima/5.31post/src
maxima-demodir=c:/maxima/share/maxima/5.31post/demo
maxima-testsdir=c:/maxima/share/maxima/5.31post/tests
maxima-docdir=c:/maxima/share/maxima/5.31post/doc
maxima-infodir=c:/maxima/info
maxima-htmldir=c:/maxima/share/maxima/5.31post/doc/html
maxima-plotdir=c:/maxima/libexec/maxima/5.31post
maxima-layout-autotools=T
maxima-userdir=C:/Documents and Settings/dabilling/maxima
maxima-tempdir=C:/Documents and Settings/dabilling
maxima-lang-subdir=NIL
maxima-objdir=C:/Documents and Settings/dabilling/maxima/binary/binary-sbcl

### From doc/info/makefile ###
exec_prefix = ${prefix}
expanded_datadir = c:/maxima/share
expanded_exec_prefix = c:/maxima
expanded_infodir = c:/maxima/share/info
expanded_libdir = c:/maxima/lib
expanded_libexecdir = c:/maxima/libexec
expanded_top_srcdir = /usr/local/src/maxima-sbcl