how to use `\marginnote` in `mdframed` environment? (follow up)

Question

I need to have a line on the INNER margin in a double-sided tufte-document. There was a close question and it has this answer. That answer is perfect. Their output is: (You see the line on the INNER part of the page)

The difference is that I use tufte-book class, but that example is for an article class. As soon as I use \marginnote{Hello} in this code snippet LaTex gives a mistake ! LaTeX Error: Not in outer par mode.

\begin{mdframed}[style=MDFStyGrayBar]
\lipsum
%\marginnote{Hello}
\lipsum
\end{mdframed}

(for the full code shamelessly stolen from the link, see below)

I wonder how to use \marginnote in mdframed environment, if possible. My search led to this question, that also doesn't have any answer.

I also have quite a number of \marginnote, marginfigure and figure* floats (with some tikz stuffing). I assume they all work the same, so I hope they will work as soon as the problem will be solved for at least one of them.

Any code modifications are welcome, as I still don't understand how that solution works anyway (I am freaking out as I see @ and code around it).

\documentclass[twoside,symmetric,notoc,justified]{tufte-book}%

\usepackage[utf8]{inputenc}
\usepackage[latin]{babel}
\usepackage[OT1]{fontenc}
\usepackage[pdftex]{graphicx}
\usepackage{lipsum}
\usepackage{float}
\usepackage{pgf,caption,calc}
\usepackage{tikz,tkz-euclide}
\usetkzobj{all}


\geometry{
  %showframe,
  paperwidth=145mm,
  paperheight=215mm,
  inner=16mm,
  outer=10mm,
  top=10mm,
  bottom=40mm,
  marginparsep=3mm,
  marginparwidth=40mm,
  includemp,
  includehead,
}
\usepackage[framemethod=TikZ]{mdframed} 
\makeatletter
\newrobustcmd*\if@mdf@pageodd@bar{%
 \zref@refused{mdf@pagelabel-\the\value{mdf@zref@counter}}%
 \ifodd\zref@extract{mdf@pagelabel-\the\value{mdf@zref@counter}}%
                    {mdf@pagevalue}%
    \setlength\mdf@rightmargin@length{\mdf@outermargin@length}%
    \setlength\mdf@leftmargin@length{\mdf@innermargin@length}%
    \mdfsetup{hidealllines=true,leftline=true}%
 \else
    \setlength\mdf@rightmargin@length{\mdf@innermargin@length}%
    \setlength\mdf@leftmargin@length{\mdf@outermargin@length}%
    \mdfsetup{hidealllines=true,rightline=true}%
 \fi%
}
\newrobustcmd*\changepageodd{\let\if@mdf@pageodd\if@mdf@pageodd@bar}
\makeatother
\mdfdefinestyle{MDFStyGrayBar}{%
    linecolor=gray,
    backgroundcolor=white,
    %
    outerlinewidth=5pt,
    %
    topline=false,
    bottomline=false,
    rightline=false,
    leftline=true,
    %
    innertopmargin=4pt, %\baselineskip
    innerbottommargin=8pt,
    innerrightmargin=3pt,
    innerleftmargin=3pt,
    %
    skipabove=\topskip,
    skipbelow=\topskip,
    settings={\changepageodd}
}
\usepackage{showframe,lipsum}
\begin{document}

\noindent Some normal text.
\begin{mdframed}[style=MDFStyGrayBar]
\lipsum
%\marginnote{Hello}
\lipsum
\end{mdframed}

\end{document}

Answer 1

The \marginnote definition of the tufte-book class is based on \marginpar. This is a float and it won't work inside a mdframed environment.

You can switch to the \marginnote definition of the marginnote package, which is not a float. Be aware that this completly overwrite the tufte-definition. So none of the tufte settings or options will apply:

\documentclass[twoside,symmetric,notoc,justified]{tufte-book}%
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}

\usepackage[framemethod=TikZ]{mdframed}


\let\marginnote\someundefinedcommand
\usepackage{marginnote}

\begin{document}


\noindent Some normal text.
\begin{mdframed}
blblb 
\marginnote{Hello}
\end{mdframed}

\end{document}