moderncv class does not compile in Debian Stretch

[Andrea Neroni <hellnote01-debian@yahoo.it>]

Hello everybody,
I used to have a personal cv written using the moderncv class from the package texlive-latex-extra,
compiled using pdflatex. After upgrading to Stretch it seems that moderncv class is using
/usr/share/texlive/texmf-dist/tex/latex/fontawesome/fontawesome.sty

that in turn uses
/usr/share/texlive/texmf-dist/tex/latex/fontspec/fontspec.sty

that can only be compiled in XeLateX or LuaLatex. Fine.
Installed texlive-xetex and compiled using xelatex. This error now pops up

LaTeX Warning: You have requested package `moderncvheadiii',
               but the package provides `moderncvheadiii'.

) (/usr/share/texlive/texmf-dist/tex/latex/moderncv/moderncvbodyiii.sty

LaTeX Warning: You have requested package `moderncvbodyiii',
               but the package provides `moderncvbodyiii'.

! Undefined control sequence.
<argument> \tiny \faCircleO 


Now, to my questions. Why is Xelatex now required, what changed in the class?

How can I solve the latter error? I believe it could be a bug in the moderncv class,
should I report it to package maintainers?


Thanks in advance to anybody answering!


Andrea