Working on network-manager-l2tp

[Jelle Licht]

Hey guix,

Seeing as a lot of people might be working from home at the moment, it
seems a good moment to look at issues that might prevent us from using
guix for that exact purpose. Right now, I can not connect to my company
vpn, which make several processes much more difficult than they need to
be.

The issue with network-manager-l2tp is that because of licensing
incompatibilities, version built with OpenSSL < 3.0 cannot be
redistributed in binary form. As people informed me previously at [1],
it seems that it is currently not possible to prevent the distribution
of substitutes using guix.

I still would like to get network-manager-l2tp packaged, as well as make
a simple service definition available. A hack that would allow us to
truly disable substitutions of certain store paths is a
solution. Another option is to simply wait until OpenSSL 3.0 is
released, although this might still take until Q4 of 2020 [3].

Any ideas?

- Jelle


[1]: http://logs.guix.gnu.org/guix/2019-10-15.log#171645
[2]: https://github.com/nm-l2tp/NetworkManager-l2tp
[3]: https://www.openssl.org/blog/blog/2019/11/07/3.0-update/