steg86 VS cross

This is a good list! Another fun quirk: because x86 is a register-memory architecture and allows all kinds of variants of reg/mem operand encodings, there are a handful of equivalent encodings with exactly the same lengths (and just slightly different ModR/M bytes). You can take advantage of this to do software fingerprinting or, in my case, steganography without changing an executable’s size or semantics[1].

[1]: https://github.com/woodruffw/steg86

A tool called cross-rs also exists, with some of the complexities you mentioned. As I understand it this is to unify the process for a wide range of targets (including e.g. Windows) and to isolate host dependencies.

Cross compiling with cargo has always been relatively simple; that's what you get by designing a default cross compiling toolchain. cargo cross also exists to make cross compilation and testing even simpler for most cases.

the qemu setup is black magic

This project is in the early development stage, but in my opinion, it is more convenient, fast, and powerful than projects like cross-rs. I am not a very good technical writer, and if something is not clear, ask me. And of course, any contributions and improvements are welcome.

cargo install has no facility for per-project installation, but Rust binaries are statically linked aside from the C libraries they depend on, so it should work if you compilie the sqlx-cli binary against the oldest glibc you want to support (cross can help there) and then copy it to the other development machines through any means desired.)

I'm no expert, but Cargo Cross might help. This uses containers to cross compile rust projects.

If you want to get it working with openssl for some reason, I would recommend using cross, but it won't do you much good by itself, as the default docker image (and therefore sysroot) doesn't have much. Given your errors, it likely doesn't come with a version of openssl. If you want to add it yourself, please look at the "Custom Docker Images" section of cross's readme page. You'll need a bit of knowledge of how to get cross compilation working on your Linux distro of choice for the docker base image. Good luck!

I've tried everything. I've tried following guides about doing it "by hand" but couldn't do it. I'm now using cargo cross as suggested by a lot of people, but it's just isn't working. I keep getting errors about OpenSSL. I've followed every suggestion possible but it's still isn't working. As per this article on the Cross wiki, I've added

Secondly, for pi's, I always use cross-rs

I'm not sure who needs to see this, but I had been struggling with compile times using cross + Docker Desktop on Mac while working on a small personal project the past few days. Despite the whole project being fewer than 350 LOC between a few files, recompiling the project with any change was taking upwards of 2 minutes through cross. I went through the due diligence of reducing the number of dependencies, removing features and macros that I didn't need, not compiling in release mode, trying different file sharing implementations for Docker Desktop and with all of that combined the time dropped to around 1 minute and 30 seconds for an incremental build. Still far from ideal for a small personal project.