RPM build fix (reverted CI changes which will need to be un-reverted or made conditional) and vendor Rust dependencies to make builds much faster in any CI system.

zeroidc/vendor/thiserror/tests/ui/from-backtrace-backtrace.rs

@@ -0,0 +1,12 @@
+// https://github.com/dtolnay/thiserror/issues/163
+
+#![feature(backtrace)]
+
+use std::backtrace::Backtrace;
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+#[error("...")]
+pub struct Error(#[from] #[backtrace] std::io::Error, Backtrace);
+
+fn main() {}