Adobe Garamond Pro and Esperanto

Question

Is it at all possible to typeset text in Esperanto language (with LuaLaTeX) using Adobe Garamond Pro font? After some research and testing it appears there is no way to do this, that some characters (such as ĉ, ŭ, ĥ) are simply missing and impossible to create even with composite commands (like \^ c).

Or is there a way around it? Thanks in advance for any help!

Edit Upon request adding MWE:

%%%! lualatex

\def\fontBaseName{adobegaramondpro}
\def\fontBaseNameBold{agaramondprosemibold}

\documentclass[11pt,twoside,openright]{book}
\usepackage{polyglossia}
\setdefaultlanguage{esperanto}
\setmainfont[BoldFont={\fontBaseNameBold}]{\fontBaseName}
\begin{document}
Antaŭparolo

Ĉi-loke estas kaj fariĝis ŝoseo estas ŝtopita teĥnike
\end{document}

The result:

Answer 1

This is a few years old, but I saw it when it landed back on the front page, and it deserves an answer. Actually, it deserves two, depending on which problem you want to solve: getting those accents in Garamond, or faking accented characters in a font that does not contain them.

You update in the comments to say that you ended up using Linotype Garamond Premier. In 2020, a free font that contains all these characters is EB Garamond. Garamond Libre would also work.

\tracinglostchars=2
\documentclass[11pt,twoside,openright]{book}
\pagestyle{empty} % Suppress page numbering.
\usepackage{polyglossia}
\setdefaultlanguage{esperanto}
\usepackage{ebgaramond}
\begin{document}
Antaŭparolo

Ĉi-loke estas kaj fariĝis ŝoseo estas ŝtopita teĥnike
\end{document}

If you are looking instead for a solution to the problem that your font does not contain combining accents (rare these days, but I have run into it), you can tell LaTeX to use non-combining accents. A MWE for your sample:

\tracinglostchars=2
\documentclass[11pt,twoside,openright]{book}
\pagestyle{empty} % Suppress page numbering.

\usepackage{polyglossia}
\usepackage{newunicodechar}
\setdefaultlanguage{esperanto}
\usepackage{ebgaramond}

\DeclareTextAccent{\^}{\UnicodeEncodingName}{"02C6} % Modifier letter circumflex accent
\DeclareTextAccent{\u}{\UnicodeEncodingName}{"02D8} % Spacing breve
\newunicodechar{Ĉ}{\^{C}}
\newunicodechar{ĝ}{\^{g}}
\newunicodechar{ŝ}{\^{s}}
\newunicodechar{ĥ}{\^{h}}
\newunicodechar{ŭ}{\u{u}}

\begin{document}
Antaŭparolo

Ĉi-loke estas kaj fariĝis ŝoseo estas ŝtopita teĥnike
\end{document}

The Unicode standard says that canonically-precomposed and decomposed characters should be equivalent, but not every font on every system implements that correctly. If a font you want to use contains combining accents, but a precomposed character does not work, delete the \DeclareTextCommand lines from the above example.