$ texindex ./main.au ./main.cp ./main.pg ./main.sb
Segmentation fault (core dumped)
$ cat texindex.exe.stackdump 
Exception: STATUS_ACCESS_VIOLATION at eip=6105440C

eax=0000004A ebx=00000003 ecx=00000013 edx=02B9E8A9 esi=00405457 edi=0040544D

ebp=0022EE08 esp=0022ED60 program=C:\cygwin\bin\texindex.exe, pid 296, thread main

cs=001B ds=0023 es=0023 fs=003B gs=0000 ss=0023

Stack trace:

Frame     Function  Args

0022EE08  6105440C  (00460210, 00000000, 0022EEC8, 6108DD7F)

0022EE18  61054685  (0040544D, 6115E684, 00000000, 00403229)

0022EEC8  6108DD7F  (00000005, 6115E684, 00460090, 77DADB0D)

0022EF78  61005BC8  (0022EFD0, 00000000, 00000002, 00000000)

0022FF88  61005EB3  (00000000, 00000000, 00000000, 00000000)

End of stack trace
$ cat main.au
\entry{baz}{1}{baz}
$ cat main.cp
\entry{foo}{1}{foo}
$ cat main.pg
\entry{bar}{1}{\code {bar}}
$ cat main.sb
\entry{sa}{1}{sa}
\entry{sb}{1}{sb}
$ cat ../main.texi
\input texinfo
@setfilename main.info
@settitle main
@defindex au
@defindex sa
@defindex sb
@synindex sa sb
@node Top
Hello walls.
@include sub.texi
@bye
$ cat ../sub.texi
@cindex foo
foo
@pindex bar
bar
@auindex baz
baz
@saindex sa
sa
@sbindex sb
sb
$ head ../texinfo.tex
% texinfo.tex -- TeX macros to handle Texinfo files.
%
% Load plain if necessary, i.e., if running under initex.
\expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi
%
\def\texinfoversion{2006-05-07.15}
%
% Copyright (C) 1985, 1986, 1988, 1990, 1991, 1992, 1993, 1994, 1995,
% 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free
% Software Foundation, Inc.