Build errors ^^^^^^^^ use of unstable library feature 'core_c_str' about firefly

[bitwalker]

I've updated the readme to address the outdated toolchain, and make a note about the CC/CXX env vars on Linux. Please reopen this issue if you are still having a problem though!

[bitwalker]

There's probably two things here (and I'll have to update the README):

1. You need a newer nightly than 2022-07-12, our CI is now using 2022-08-08
2. You'll want to make sure clang is used to compile the project, so make sure you set CC=/path/to/untarred/clang CXX=/path/to/untarred/clang++ when running cargo make firefly

As an aside, I see you added the wasm32-unknown-unknown toolchain, but just as a heads up - our runtime isn't compatible with wasm32 just yet (this is coming soon, but our current runtime is tailored for compiler development on AArch64/x86_64, and is not only barebones, but uses an implementation of stack switching that isn't portable to wasm32). I just finished work on the compiler this week, so all of this is being addressed in my next round of work, but just wanted to make sure expectations are set :)