On 2025-02-12 22:45, lilydjwg wrote:
> cat: -: input file is output file

Thanks for the bug report. The symptoms you observe are a bug in 'cat'. 
I also see a bug in Gawk which I reported to the Gawk maintainer 
<https://lists.gnu.org/r/bug-gawk/2025-02/msg00003.html>. I don't see a 
bug in zsh or fish but perhaps I'm missing something.

To fix the 'cat' bug I installed the attached patch into bleeding-edge 
Coreutils on Savannah, and something like this patch should appear in 
the next release.