fort77 software package provides Invoke f2c like a real compiler, 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 fort77
fort77 is installed in your system.
Make ensure the fort77 package were installed using the commands given below,
$ sudo dpkg-query -l | grep fort77 *
You will get with fort77 package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Development |
| Package | fort77 |
| Version | 1.15-11 |
| Description | Invoke f2c like a real compiler |
| Sub Section | devel |