docbook2X: iconv: (stdin): cannot convert

[Jim Osborn <jimo@eskimo.com>]

After installing docbook2X-0.8.5 I tried the suggested two-part
invocation of docbook2man on a file in the test/refentry directory:

  db2x_xsltproc -s man -o sgml2xml.mxml sgml2xml.xml

successfully makes sgml2xml.mxml.  But then

  db2x_manxml sgml2xml.mxml

fails with this message:

  iconv: (stdin): cannot convert
  /usr/local/bin/db2x_manxml: program in pipeline exited with an error

I've tried every permutation of --iconv-program=/usr/local/bin/iconv
and --encoding="us-ascii//TRANSLIT" to no avail.  I can run

  utf8trans /usr/local/share/docbook2X/charmaps/roff.charmap <sgml2xml.mxml

with no errors, for what that's worth.

I've got these installed:

OpenSP-1.5.2 and openjade-1.3.2
docbook-xsl-1.69.1
libiconv 1.9.1
glibc 2.2.4

xsltproc --version shows this:
  Using libxml 20622, libxslt 10115 and libexslt 812
  xsltproc was compiled against libxml 20622, libxslt 10115 and libexslt 812
  libxslt 10115 was compiled against libxml 20622
  libexslt 812 was compiled against libxml 20622

I'm out of ideas how to proceed debugging this issue, so I'd really
appreciate some pointers.

TIA,

Jim