This is pdfTeX, Version 3.14159265-2.6-1.40.20 (TeX Live 2019) (preloaded format=pdftex 2019.5.8)  16 JUN 2019 21:04
entering extended mode
 restricted \write18 enabled.
 %&-line parsing enabled.
**test.tex
(./test.tex
! TeX capacity exceeded, sorry [input stack size=5000].
\subpre ...by -1 \ifnum \columns >0 \span \subpre 
                                                  \fi 
\subpre ...by -1 \ifnum \columns >0 \span \subpre 
                                                  \fi 
\subpre ...by -1 \ifnum \columns >0 \span \subpre 
                                                  \fi 
\subpre ...by -1 \ifnum \columns >0 \span \subpre 
                                                  \fi 
\subpre ...by -1 \ifnum \columns >0 \span \subpre 
                                                  \fi 
\subpre ...by -1 \ifnum \columns >0 \span \subpre 
                                                  \fi 
...
l.13 \halign{\span\preamb
                         
If you really absolutely need more capacity,
you can ask a wizard to enlarge me.

!  ==> Fatal error occurred, no output PDF file produced!