Description of the problem / feature request:

I intend to add support for .ar archive files and .deb files (which are the same file format).

Feature requests: what underlying problem are you trying to solve with this feature?

download_and_extract supports many compressed or packaged file formats already. Adding .ar and .deb files will make it easier for toolchains to download and extract .deb files into their sysroot without requiring an external tool.

Example hermetic toolchain that downloads .deb files and extracts them.

Have you found anything relevant by searching the web?

Apache Commons Compress already has support for .ar files and this package is already used by Bazel for Compressed Tar files so we shouldn't need any additional third party dependencies.