fontspec Font not Found (AlegreyaSans package)

Question

This is a common problem, but none of the several links I've followed address my issue. An MWE:

%XeLaTeX
\documentclass{standalone}
\usepackage[T1]{fontenc}
\usepackage[sfdefault]{AlegreyaSans}
%\usepackage{Alegreya} % this works fine!

\begin{document}
Test!
\end{document}

I get the error message:

! Undefined control sequence.
<argument> ... AlegreyaSansSC-\Alegreya@boldstyle 
                                                  }, ItalicFeatures = { Smal...
l.151       {AlegreyaSans}

The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

! Undefined control sequence.
<argument> ... AlegreyaSansSC-\Alegreya@boldstyle 
                                                  Italic }, 
l.151       {AlegreyaSans}

The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

Requested font "[AlegreyaSans-Regular.ttf]/OT" at 10.0pt
 -> /usr/local/texlive/2016/texmf-dist/fonts/truetype/huerta/alegreya/AlegreyaSans-Regular.ttf
\g__fontspec_family_AlegreyaSans_int=\count124
Requested font "[AlegreyaSansSC-Regular.ttf]/OT" at 10.0pt
 -> /usr/local/texlive/2016/texmf-dist/fonts/truetype/huerta/alegreya/AlegreyaSansSC-Regular.ttf
Requested font "[AlegreyaSans-Bold.ttf]/OT" at 10.0pt
 -> /usr/local/texlive/2016/texmf-dist/fonts/truetype/huerta/alegreya/AlegreyaSans-Bold.ttf
Requested font "[AlegreyaSansSC-.ttf]/OT" at 10.0pt
 -> font not found, using "nullfont"

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
! fontspec error: "font-not-found"
! 
! The font "AlegreyaSansSC-" cannot be found.

What I don't understand is that, for instance, /usr/local/texlive/2016/texmf-dist/fonts/truetype/huerta/alegreya/AlegreyaSans-Regular.ttf absolutely exists! Is it possible that there is a permissions issue preventing this file from being accessed?

I'm using TeXlive 2016 on Fedora 24; I don't have this problem on a Mac with TeXlive 2015; is this a bug of some kind?

Answer 1

Update

The issue described below has been fixed in AlegreyaSans.sty released 2016/09/15.

Original answer

It's a bug in AlegreyaSans.sty; in a few places the macro

\Alegreya@boldstyle

is used instead of \AlegreyaSans@boldstyle.

You should make a bug report; in the meantime, using the fact that the undefined control sequence is first used when \setsansfont is performed, you can work around the issue with the following trick:

\documentclass{standalone}
\usepackage[T1]{fontenc}

%%% Fix for the bug in AlegreyaSans
% make sure \setsansfont is defined
\usepackage{fontspec}
% start the fix by temporarily redefining
% \setsansfont to define the wrong macro
% to be the same as the right one
\makeatletter
% save a copy of \setsansfont
\let\fontspec@setsansfont\setsansfont
% redefine it to fix the issue and to redefine
% itself to the original one
\def\setsansfont{%
  \let\Alegreya@boldstyle\AlegreyaSans@boldstyle
  \let\setsansfont\fontspec@setsansfont
  \setsansfont
}
\makeatother
%%% end of fix, now load AlegreyaSans

\usepackage[sfdefault]{AlegreyaSans}

\begin{document}
Test!
\end{document}