Error message when definition is missing about acro HOT 10 CLOSED

#!latex

\documentclass{article}
\usepackage{acro}
\begin{document}

\ac{foo}

\end{document}

#!latex

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
! acro error: "undefined"
! 
! You've requested acronym `foo' but it seems that it was never defined!
! 
! See the acro documentation for further information.
! 
! For immediate help type H <return>.
!...............................................  
                                                  
l.5 \ac{foo}

#!latex

\documentclass{article}
\usepackage{acro}

\ExplSyntaxOn
\bool_new:N \l_acro_warned_bool
\cs_set_protected:Npn \acro_defined:n #1
  {
    \bool_if:nTF
      {
        !\l_acro_warned_bool &&
        !\prop_if_in_p:Nn \l__acro_short_prop {#1}
      }
      {
        \msg_warning:nnn {acro} {undefined} {#1}
        \textbf {[#1]}
        \bool_set_true:N \l_acro_warned_bool
      }
      { \bool_set_false:N \l_acro_warned_bool }
  }
\ExplSyntaxOff

\begin{document}

\ac{foo}

\end{document}

#!latex


*************************************************
* acro warning: "undefined"
* 
* You've requested acronym `foo' but it seems that it was never defined!
*************************************************

#!latex

\documentclass{article}
\usepackage{acro}

\ExplSyntaxOn
\bool_new:N \l_acro_warned_bool

\msg_set:nnn {acro} {undefined}
  {
    You've~requested~acronym~`#1'~\msg_line_context: \c_space_tl
    but~you~ apparently~haven't~defined~it,~yet!~
    Maybe~you've~mispelled~it?
  }

\cs_set_protected:Npn \acro_defined:n #1
  {
    \bool_if:nTF
      {
        !\l_acro_warned_bool &&
        !\prop_if_in_p:Nn \l__acro_short_prop {#1}
      }
      {
        \msg_warning:nnn {acro} {undefined} {#1}
        \textbf {[#1]}
        \bool_set_true:N \l_acro_warned_bool
      }
      { \bool_set_false:N \l_acro_warned_bool }
  }
\ExplSyntaxOff

\begin{document}

\ac{foo}

\end{document}

#!latex


*************************************************
* acro warning: "undefined"
* 
* You've requested acronym `foo' on line 32 but you apparently haven't defined
* it, yet! Maybe you've mispelled it?
*************************************************

#!

Package amsmath Warning: Foreign command \atop;
(amsmath)                \frac or \genfrac should be used instead
(amsmath)                 on input line 97.

#!latex

\documentclass{article}
\usepackage{acro}
\begin{document}

\ac{foo}

\end{document}

#!latex

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
! acro error: "undefined"
! 
! You've requested acronym `foo' but it seems that it was never defined!
! 
! See the acro documentation for further information.
! 
! For immediate help type H <return>.
!...............................................  
                                                  
l.5 \ac{foo}
            
|'''''''''''''''''''''''''''''''''''''''''''''''
| You've requested acronym `foo' on line 5 but you apperantly haven't defined
| it, yet! Maybe you've mispelled it?
|...............................................


!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
! acro error: "undefined"
! 
! You've requested acronym `foo' but it seems that it was never defined!
! 
! See the acro documentation for further information.
! 
! For immediate help type H <return>.
!...............................................  
                                                  
l.5 \ac{foo}
            
|'''''''''''''''''''''''''''''''''''''''''''''''
| You've requested acronym `foo' on line 5 but you apperantly haven't defined
| it, yet! Maybe you've mispelled it?
|...............................................

#!latex

*************************************************
* acro warning: "undefined"
* 
* You've requested acronym `foo' on line 47 but you apparently haven't defined
* it, yet! Maybe you've mispelled it?
*************************************************