Avoid pulling tokio crate with loom.

tokio-rs/tokio#2463

nr/Cargo.toml

@@ -25,6 +25,11 @@ static_assertions = "1.1.0"
 loom = { git = "https://github.com/gz/loom.git", branch = "try_recv" }
 arr_macro = "0.1.3"
 
+[target.'cfg(not(loom))'.dependencies]
+# Config based dependency due to https://github.com/tokio-rs/tokio/issues/2463
+tokio = {version = "1.11.0", features = ["rt", "macros"]}
+futures = "0.3.17"
+
 # Add debug symbols on the release build so that we can debug performance issues
 [profile.release]
 debug = true
@@ -33,8 +38,6 @@ debug = true
 chashmap = "2.2"
 rand = {version = "0.8", features = ["small_rng"]}
 env_logger = "0.9.0"
-tokio = {version = "1.11.0", features = ["rt", "macros"]}
-futures = "0.3.17"
 
 [features]
 unstable = []