Bootstrappable bitcoin release builds with Guix

[Carl Dong]

Hi all,

I've been on a quest to use Guix for Bitcoin Core's reproducible builds as I
believe that Guix's focus on bootstrappability, and Guile's simplicity and
flexibility are very desirable qualities in building an auditable, secure, and
reliable build process. My pull request (very short thanks to Guix's
infrastructure) can be found here:
https://github.com/bitcoin/bitcoin/pull/15277/files

I've submitted patches for the Guix bitcoin-core package to make it
reproducible, which seems to work fine. However, for easier acceptance into the
bitcoin core process, I need to produce tarballs like the ones we have on our
servers today: https://bitcoincore.org/bin/bitcoin-core-0.17.1/

For some context, we have a "mini-guix" of sorts seen in our "depends tree"
here: https://github.com/bitcoin/bitcoin/tree/master/depends. This builds all
the dependencies for bitcoin just the way we want them, in preparation for
getting linked into bitcoin itself.

My current approach for the build process is to produce a Guix container in
which I execute a build of our "depends tree" followed by a build of bitcoin
itself. See the Guix manifest and scripts here:
https://github.com/bitcoin/bitcoin/pull/15277/files

However, there were three hiccups that I had to hack my way around:

1. libstdc++ would not link statically even with "-static-libstdc++". The hack
   was to remove the .la file under $LIBRARY_PATH.

2. Upon inspection of the binaries produced at the end of this process, they all
   had rpaths. The hack was to use patchelf --remove-rpath on them.

3. Upon inspection of the binaries produced at the end of this process, their
   interpreters all had a `/gnu/store/blahblah-glibc-2.28' prefix. The hack was
   to use patchelf --set-interpreter on them.

My questions are:

1. Is there a way to avoid the hacks that I listed above? I understand that it
   might mean writing custom gcc packages and I'm 100% okay with that.

2. Is there an easier way of achieving the same thing?

Thank you all in advance for helping with this, and I hope that we'll see
boostrappable Guix release builds of bitcoin very soon!

Cheers,
Carl Dong
address@hidden
"I fight for the users"