Nightly requirement on backtraces

[arcanis]

I noticed that std::backtrace::Backtrace was standardized, but thiserror seems to still require a nightly build and special feature to have support for #[backtrace] - is that expected? Is there a way to have a (prehaps just basic) support for stacktrace captures from within the From implementation using only stable features?

[dtolnay]

It is expected. Only the Backtrace type has been stabilized so far, not backtraces in the Error trait.

Storing backtraces in From without exposing them in the Error impl is not supported, but you can write your own From impls or use a different From derive macro to do this.