Merge pull request #438 from DanielEScherzer/patch-1

Remove backtrace dependency, always unused

Author: dtolnay

Cargo.toml

@@ -14,13 +14,9 @@ rust-version = "1.68"
 [features]
 default = ["std"]
 std = []
-
-[dependencies]
-# On compilers older than 1.65, features=["backtrace"] may be used to enable
-# backtraces via the `backtrace` crate. This feature has no effect on 1.65+
-# besides bringing in an unused dependency, as `std::backtrace` is always
-# preferred.
-backtrace = { version = "0.3.51", optional = true }
+# Compatibility with the old backtrace optional dependency; allow
+# specifying backtrace as a feature without breaking
+backtrace = []
 
 [dev-dependencies]
 futures = { version = "0.3", default-features = false }