Unitialized variable

[Karl Berry]

    xetex: error while loading shared libraries: libfontconfig.so.1: cannot 
    open shared object file: No such file or directory

Oh. Well, our x86_64-linux xetex binary is linked with libfontconfig
because it's the fundamental library for looking up (system) fonts. If
you don't have it, xetex won't run. So you either need to find it for
WSL, or you might as well remove the xetex packages. There is no other
(real) solution.

In fact, the question in my mind now is how any of the xetex formats
ever got built or rebuilt in the first place. For example, what does
tlmgr-commands.log say about xetex.fmt or xelatex.fmt? 

Or did you try to eliminate all xetex formats and packages in the first
place, and this stray was the only one left behind?

    deeper--it appears to be with the error logging 

The Perl warning in itself is not important. We should protect against
it, but the missing libfontconfig is the only real problem here.

    (and maybe the script should check for this library file before it
    starts running stuff?).

What it needs to protect against is executable files that are supposed
to be runnable actually being runnable. Checking for individual
libraries wouldn't be feasible. --thanks, karl.