c-compiler-alpha-linux-gnu software package provides virtual package provided by gcc-6-alpha-linux-gnu, gcc-5-alpha-linux-gnu, 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 c-compiler-alpha-linux-gnu
c-compiler-alpha-linux-gnu is installed in your system.
Make ensure the c-compiler-alpha-linux-gnu package were installed using the commands given below,
$ sudo dpkg-query -l | grep c-compiler-alpha-linux-gnu*
You will get with c-compiler-alpha-linux-gnu package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Virtual packages |
| Package | c-compiler-alpha-linux-gnu |
| Version | |
| Description | virtual package provided by gcc-6-alpha-linux-gnu, gcc-5-alpha-linux-gnu |
| Sub Section | Virtual |