xdt-autogen: configure.ac\001: No such file or directory

xdt-autogen seems to have a problem at least when running on macOS 10.15.7 with its version of /bin/sh which is "GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin19)".

I tried xdt-autogen from xfce4-dev-tools 4.16.0 and 4.17.0.

When running xdt-autogen in the libxfce4util 4.16.0 source directory, it prints a bunch of nonsense like this:

egrep: /path/to/libxfce4util-4.16.0/configure.ac\001: No such file or directory
grep: /path/to/libxfce4util-4.16.0/configure.ac\001: No such file or directory
grep: /path/to/libxfce4util-4.16.0/configure.ac\001: No such file or directory
grep: /path/to/libxfce4util-4.16.0/configure.ac\001: No such file or directory
Preparing package directory /path/to/libxfce4util-4.16.0...
egrep: /path/to/libxfce4util-4.16.0/configure.ac\001: No such file or directory
grep: /path/to/libxfce4util-4.16.0/configure.ac\001: No such file or directory
Running autoreconf...
autoreconf: export WARNINGS=
autoreconf: Entering directory '.'
autoreconf: configure.ac: not using Gettext
^C

I gather that xdt-autogen would like to check whether configure.ac contains various things, but it's not getting very far since it has erroneously tacked a \001 onto the end of the filename.