On 07/06/2017 11:14, Alexander Grahn wrote:

> Good afternoon,

> 

> the recent version change of expl3 from [2017/04/01] (last TL-16 state) to

> [2017/05/13] (initial TL-17 state) changed the behaviour of \hbox_s:Nn, which

> made a hot-fix necessary for one of my packages (ocgx2) on CTAN.

> 

> The problem boils down to the following code, which used to work with expl3 as

> of v. 2017/04/01, but fails now with `! Missing } inserted.' error.

> 

>   \documentclass{article}

>   \usepackage{hyperref}

>   

>   \usepackage{expl3}

>   \ExplSyntaxOn

>   

>   \begin{document}

>   

>   \href{https://www.ctan.org}{\dots

>     \hbox_set:Nn0\bgroup CTAN    % broken since expl3 [2017/05/13]

>   %  \setbox0=\hbox\bgroup CTAN  % hot-fix

>     \egroup\box_use:N0

>   \dots}

>   

>   \end{document}

> 

> I would like to return to using \hbox_set:Nn instead of \setbox.

> 

> Alexander



Hi Alexander,



I had an issue in siunitx which I also had to fix for this update: for

me it boiled down to having made some implementation assumptions and

ending up mixing different interfaces. In the above, \hbox_set:Nn is

wrong (even if we ignore using "0" not a box name). For me



  \href{https://www.ctan.org}{\dots

    \hbox_set:Nw 0 CTAN    % broken since expl3 [2017/05/13]

  %  \setbox0=\hbox\bgroup CTAN  % hot-fix

    \hbox_set_end:

    \box_use:N0

  \dots}



works and is using the appropriate interface.



Joseph



P.S. I'm meant to be adding \hbox_set_to_wd:Nnw, etc., as those are

currently not covered: will aim to do today/tomorrow.