This reverts commit 4fca306397.
Something in the BLST update is causing SIGILLs on aarch64 non-portable builds. While we debug the issue, I think it's best if we just revert the update.
## Issue Addressed
Closes#1504
Closes https://github.com/sigp/lighthouse/issues/1505
## Proposed Changes
* Update `blst` to the latest version, which is more portable and includes finer-grained compilation controls (see below).
* Detect the case where a binary has been explicitly compiled with ADX support but it's missing at runtime, and report a nicer error than `SIGILL`.
## Known Issues
* None. The previous issue with `make build-aarch64` (https://github.com/supranational/blst/issues/27), has been resolved.
## Additional Info
I think we should tweak our release process and our Docker builds so that we provide two options:
Binaries:
* `lighthouse`: compiled with `modern`/`force-adx`, for CPUs 2013 and newer
* `lighthouse-portable`: compiled with `portable` for older CPUs
Docker images:
* `sigp/lighthouse:latest`: multi-arch image with `modern` x86_64 and vanilla aarch64 binary
* `sigp/lighthouse:latest-portable`: multi-arch image with `portable` builds for x86_64 and aarch64
And relevant Docker images for the releases (as per https://github.com/sigp/lighthouse/pull/1574#issuecomment-687766141), tagged `v0.x.y` and `v0.x.y-portable`
## Issue Addressed
NA
## Proposed Changes
Adds support for using the [`cross`](https://github.com/rust-embedded/cross) project to produce cross-compiled binaries using Docker images.
Provides quite clean and simple cross-compiles cause all the complexity is hidden in Dockerfiles. It does require you to be in the `docker` group though.
## Details
- Adds shortcut commands to `Makefile`
- Ensures `reqwest` and `discv5` use vendored openssl libs (i.e., static not shared).
- Switches to a [commit](284f705964) of blst that has a renamed C function to avoid a collision with openssl (upstream issue: https://github.com/supranational/blst/issues/21).
- Updates `ring` to the latest satisfiable version, since an earlier version was causing issues with `cross`.
- Off-topic, but adds extra message about Windows support as suggested by Discord user.
## Additional Info
- ~~Blocked on #1495~~
- There are no tests in CI for this yet for a few reasons:
- I'm hesitant to add more long-running tasks.
- Short-term bitrot should be avoided since we'll use it each release.
- In the long term I think it would be good to automate binary creation on a release.
- I observed the binaries increase in size from 50mb to 52mb after these changes.
