This (original email below) turned out to be a general cygwin issue, not 
a gawk issue:

$ LC_ALL=C sed 's/x/y/' $(seq 1000000)
Segmentation fault (core dumped)

$ LC_ALL=C grep 'foo' $(seq 1000000)
Segmentation fault (core dumped)

Regards,

     Ed.

-------- Forwarded Message --------
Subject: 	gawk core dumped on too many input values
Date: 	Sun, 27 Aug 2023 08:09:54 -0500
From: 	Ed Morton <mortoneccc@comcast.net>
To: 	bug-gawk@gnu.org <bug-gawk@gnu.org>



Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: cygwin
Compiler: gcc
Compilation CFLAGS: -ggdb -O2 -pipe -Wall -Werror=format-security 
-Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-strong 
--param=ssp-buffer-size=4 
-fdebug-prefix-map=/cygdrive/d/a/scallywag/gawk/gawk-5.2.2-1.x86_64/build=/usr/src/debug/gawk-5.2.2-1 
-fdebug-prefix-map=/cygdrive/d/a/scallywag/gawk/gawk-5.2.2-1.x86_64/src/gawk-5.2.2=/usr/src/debug/gawk-5.2.2-1 
-DNDEBUG
uname output: CYGWIN_NT-10.0-22621 TournaMart_2023 3.4.8-1.x86_64 
2023-08-17 17:02 UTC x86_64 Cygwin
Machine Type: x86_64-pc-cygwin

Gawk Version: 5.2.2

Attestation 1:
         I have read 
https://www.gnu.org/software/gawk/manual/html_node/Bugs.html.
         Yes

Attestation 2:
         I have not modified the sources before building gawk.
         True

Description:
         I was trying to test something related to ARG_MAX when I ran the
         awk script below and it core dumped instead of reporting an error
         and exiting gracefully. In case it's useful getconf ARG_MAX outputs
         32000.

Repeat-By:
         $ LC_ALL=C awk 'BEGIN{print ARGC}' $(seq 1000000)
         Segmentation fault (core dumped)