[tex-k] [BUG ε-TeX of tl2021] \numexpr failing on unary minus

[Ilya Zakharevich]

 [ This address is reported on https://ctan.org/pkg/etex to be the bug
   tracker.  Sorry if I’m using a wrong address.  The workaround for
   the bug is to explicitly multiply by (-1). ]

The following content:

   \the\numexpr -(-1)\relax

produces the following error message:

   This is pdfTeX, Version 3.141592653-2.6-1.40.22 (TeX Live 2021/W32TeX) (preloaded format=pdflatex)
     restricted \write18 enabled.
   entering extended mode
   (./bug_numexpr.tex
   LaTeX2e <2020-10-01> patch level 4
   L3 programming layer <2021-02-18>
   ! Missing number, treated as zero.
   <to be read again>
                      (
   l.1 \the\numexpr -(
                      -1)\relax

Thanks,
Ilya

P.S.  I’m not subscribed…