autoconf2.64 software package provides automatic configure script builder (obsolete version), you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install autoconf2.64
autoconf2.64 is installed in your system.
Make ensure the autoconf2.64 package were installed using the commands given below,
$ sudo dpkg-query -l | grep autoconf2.64 *
You will get with autoconf2.64 package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Development |
| Package | autoconf2.64 |
| Version | 2.64+dfsg-0.1 |
| Description | automatic configure script builder (obsolete version) |
| Sub Section | devel |