pandoc/test/command/3236.md

% pandoc -f latex -t native
\newcommand{\mycolor}{red}

\includegraphics[width=17cm]{\mycolor /header}
Magnificent \mycolor{} header.
^D
[ Para
    [ Image
        ( "" , [] , [ ( "width" , "17cm" ) ] )
        [ Str "image" ]
        ( "red/header" , "" )
    , SoftBreak
    , Str "Magnificent red header."
    ]
]