bug#51454: Progress bar in Org source blocks

[excalamus]

> I miss what you would like or what you are expecting.  
>
My goal has been to clean up the guix command output as seen in an org-babel 
results block.  I'm blogging about Guix using org-babel and Org's export 
functionality. I want the shell output as seen in the final html to be a 
reasonable approximation of the shell output a user would see if the command 
were run in something like xterm.  Based on feedback from people in the Org 
community, I thought there might be a way to toggle off certain characters.

> And I do not think it is an issue about Guix.  Instead, it is an issue about
> dealing with outputs and Org-mode (Babel). 
>
I agree that handling this in org makes sense. When I asked the Org people, 
they had said it was a Guix issue. And with what we found with NO_COLOR, fair 
enough. You also raise a good point, however, that the characters originate 
upstream. Anything Guix might do would be a work around and work arounds are 
probably best handled in Emacs.

>  for instance, something along these lines...
>
Thank you for the example. I was unaware of the Emacs function 
ansi-color-apply-on-region.  The rest can probably be handled with 
replace-match.

I appreciate all your help. Thank you, Simon!