> For me it's the borrow checker and lack of shared mutable states stopping me from doing dumb things.
AFAIK, the newest SPARK got borrow checking capability. Also, Ada has excellent design by contract capabilities [1] and constrained subtypes [2].
> Add on things like cargo build manager and crates and it's like a delicious roast dinner smothered in gravy.
Ada has now Alire [3] for that.
> I've written in Ada95 back in college and it was great but I'm like a duck in water with Rust.
Ada is nearing the 2022 standard now. It changed a lot since 95.
PS. I have nothing against you liking Rust. Just wanted to clarify few things.
[1] https://learn.adacore.com/courses/intro-to-ada/chapters/cont...
[2] https://learn.adacore.com/courses/intro-to-ada/chapters/stro...