[XeTeX] 'regular' font not found

[Alex Lubberts]

Hi,

I recently installed XeTeX. After updating the build dependencies,
building the package for Ubuntu from source went smoothly on my AMD64.

However, it seems like the 'regular' fonts are not found. If I choose a
font with optical sizes the caption font is chosen instead of the text
font. With fonts that don't come in different sizes, I have troubles as
well: instead of selecting Gill Sans, XeTeX selects Gill Sans Condensed.

As a test I tried the file:
-----
\def\test#1#2{
  \font\x="#2" at #1 \x
    Font “#2”; is actually \fontname\x.\par}

\test{6pt}{Garamond Premier Pro}
\test{11pt}{Garamond Premier Pro}
\test{18pt}{Garamond Premier Pro}

\test{6pt}{Chaparral Pro}
\test{11pt}{Chaparral Pro}
\test{18pt}{Chaparral Pro}

\test{6pt}{Gill Sans Std}
\test{11pt}{Gill Sans Std}
\test{18pt}{Gill Sans Std}

\bye
-----

After running XeTeX, the pdf shows:
-----
Font “Garamond Premier Pro”; is actually "GaramondPremrPro-Capt" at
6.0pt.
Font “Garamond Premier Pro”; is actually "GaramondPremrPro-Capt" at
11.0pt.
Font “Garamond Premier Pro”; is actually "GaramondPremrPro-Subh"
at 18.0pt.

Font “Chaparral Pro”; is actually "ChaparralPro-Capt" at 6.0pt.
Font “Chaparral Pro”; is actually "ChaparralPro-Subh" at 11.0pt.
Font “Chaparral Pro”; is actually "ChaparralPro-Subh" at 18.0pt.

Font “Gill Sans Std”; is actually "GillSansStd-Condensed" at 6.0pt.
Font “Gill Sans Std”; is actually "GillSansStd-Condensed" at 11.0pt.
Font “Gill Sans Std”; is actually "GillSansStd-Condensed" at 18.0pt.
-----

Why does this happen? And what is the solution?

Appreciating any help; thanks.

Kind regards,
Alex Lubberts