Figuring out Xetex fonts under Debian

Question

I have been trying to start using xelatex.

My configuration:

Debian: testing
Texlive: 2013.20140408-1 

Taking the minimal example from

unicode-math and amsmath environments viz

\documentclass{article}
\usepackage{amsmath}
\usepackage{unicode-math}
\setmathfont{XITS Math}
\usepackage{xltxtra}

\begin{document}

\begin{equation}
    α = \beta^2_i + β^2_i
\end{equation}

\end{document}

and running xelatex on it I get:

kpathsea:make_tex: Invalid fontname `XITS Math/ICU', contains ' '

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
! fontspec error: "font-not-found"
!
! The font "XITS Math" cannot be found.
!
! See the fontspec documentation for further information.
!
! For immediate help type H <return>.
!...............................................  

l.4 \setmathfont{XITS Math}

?

With some help from comp.text.tex, I tried replacing the: \setmathfont{XITS Math} with

\setmathfont{XITS}

\setmathfont{xits-math}

None of this worked until I tried: \setmathfont{xits-math.otf}

Can you point me someplace where I can study how to specify xetex fonts under debian?

I was pointed to: texdocs which is evidently needed for linux users. However, the file which I am supposed to copy to /etc:

/var/lib/texmf/fonts/conf/texlive-fontconfig.conf does not exist on my system.

So, in addition to figuring out how to handle xetex fonts in debian, my more general question is:

Would you recommend that I dump Debian's texlive and move to a CTAN download?

Answer 1

I'm currently on Debian (testing), where I installed a full TeX Live with

apt-get install texlive-full

From what I can get, it seems that only some fonts are made visible to the system with an entry in /etc/fonts/conf.d

The relevant entries are

/etc/fonts/conf.d/65-fonts-lmodern.conf
/etc/fonts/conf.d/65-fonts-persian.conf
/etc/fonts/conf.d/65-fonts-texgyre.conf

and, indeed, if I try

\setmainfont{Latin Modern Roman}

or

\setmainfont{TeX Gyre Termes}

I get what's expected, because these fonts have been made known to the OS. Unfortunately, probably due to time limitation on the maintainer of TeX Live/Debian (our heroic Norbert Preining), only some font families are registered in /etc/fonts/conf.d

If you install a full vanilla TeX Live from TUG, then the method of adding the provided configuration file to /etc/conf.d should allow you to call all fonts by name. Fonts not made known to the OS must be called by file name, I'm afraid.

Answer 2

The answers given are already more or less the truth: Fonts shipped in /usr/share/texlive/texmf-dist are not made available automatically to fontconfig on Debian. Adding all fonts by simply adding the respective truetype/opentype directories to the fontconfig path is unfortunately a no-go, since some fonts would break the rest of the system (duplicate names, broken format, lots of problems).

What one could do it select certain fonts and make those available, but which fonts would one select? Debian has so many use cases and selecting only some fonts based on personal preference is sub-optimal and would probably only increase the confusion ("why is font A available and font B not?").

The simple solution and the one I am taking on my own computer is to add a file /etc/fonts/local.conf that contains those directories I want to activate, in my case:

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
        <dir>/usr/share/texlive/texmf-dist/fonts/opentype/adobe</dir>
        <dir>/usr/share/texlive/texmf-dist/fonts/opentype/nowacki</dir>
        <dir>/usr/share/texlive/texmf-dist/fonts/opentype/gust</dir>
        <dir>/usr/share/texlive/texmf-dist/fonts/opentype/public/fira</dir>
        <dir>/usr/share/texlive/texmf-dist/fonts/truetype/tibetan</dir>
</fontconfig>