Consider adding ability to build libressl instead

[ZoeyR]

Currently this crate only supports downloading and building the openssl source. It might be useful for upstream projects (like openssl-sys) if this crate could be set to build libressl instead.

[sfackler]

How would this be useful for upstream projects like openssl-sys?

[ZoeyR]

openssl-sys supports dynamic linking to libressl and has a feature to instead use a bundled openssl. There is no way to use the bundled feature to bundle in libressl.

[sfackler]

The point of the vendored feature is to "just make it work in a portable way". If someone cares enough about the library choice to explicitly want libressl, it seems like they can built it themselves.

[BusyJay]

I write a crate that provides libressl sources for openssl: https://github.com/BusyJay/libressl-src. Currently it can be integrated into openssl-sys by the replace or patch configuration of cargo.

I also feel OK to merge the project into openssl-src if there is a way to do it.