[tlbuild] How should xetex find texlive fonts?

[Ken Brown]

I'm trying to test my build of xetex for cygwin, so I did a test install 
of TL2009 and tried to compile 
/usr/local/texlive/2009/texmf-dist/tex/xetex/xetexfontinfo/opentype-info.tex. 
  The result was:

$ xetex opentype-info.tex
This is XeTeX, Version 3.1415926-2.2-0.9994.0 (TeX Live 2009)
  restricted \write18 enabled.
entering extended mode
(./opentype-info.texkpathsea: Invalid fontname `Latin Modern Roman/ICU', 
contains ' '

! Font \testfont="Latin Modern Roman/ICU" at 12.0pt not loadable: Metric 
(TFM)
file or installed font not found.
l.26 \font\testfont="\myfontname/ICU" at 12pt

Following advice I found on the xetex mailing list related to this error 
message, I created a .fonts.conf file:

$ cat .fonts.conf
<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
  <fontconfig>
    <dir>/usr/local/texlive/2009/texmf-dist/fonts/opentype</dir>
    <dir>/usr/local/texlive/2009/texmf-dist/fonts/truetype</dir>
    <dir>/usr/local/texlive/2009/texmf-dist/fonts/type1</dir>
</fontconfig>

I then ran xetex again and it worked.  Why didn't it just work OOTB?  Is 
there a problem with my build?  Or should something have happened during 
the install so that xetex would be able to find the fonts that are 
shipped with texlive?  I didn't find any error messages in install-tl.log.

Ken