Use the rustc unknown lints attribute

The clippy unknown lints attribute was deprecated in
nightly in rust-lang/rust#80524. The old lint name now produces a
warning.

Since we're using `allow(unknown_lints)` to suppress warnings, we need to
add the canonical name, so we can continue to build without warnings on
nightly.

But we also need to keep the old name, so we can continue to build
without warnings on stable.

And therefore, we also need to disable the "removed lints" warning,
otherwise we'll get warnings about the old name on nightly.

We'll need to keep this transitional clippy config until rustc 1.51 is
stable.

zebra-chain/src/lib.rs

@@ -9,7 +9,13 @@
 // #![deny(missing_docs)]
 #![allow(clippy::try_err)]
 // Disable some broken or unwanted clippy nightly lints
+// Build without warnings on nightly 2021-01-17 and later and stable 1.51 and later
+#![allow(unknown_lints)]
+// Disable old lint warnings on nightly until 1.51 is stable
+#![allow(renamed_and_removed_lints)]
+// Use the old lint name to build without warnings on stable until 1.51 is stable
 #![allow(clippy::unknown_clippy_lints)]
+// The actual lints we want to disable
 #![allow(clippy::from_iter_instead_of_collect)]
 #![allow(clippy::unnecessary_wraps)]
 

zebra-consensus/src/lib.rs

@@ -37,7 +37,13 @@
 //#![deny(missing_docs)]
 #![allow(clippy::try_err)]
 // Disable some broken or unwanted clippy nightly lints
+// Build without warnings on nightly 2021-01-17 and later and stable 1.51 and later
+#![allow(unknown_lints)]
+// Disable old lint warnings on nightly until 1.51 is stable
+#![allow(renamed_and_removed_lints)]
+// Use the old lint name to build without warnings on stable until 1.51 is stable
 #![allow(clippy::unknown_clippy_lints)]
+// The actual lints we want to disable
 #![allow(clippy::unnecessary_wraps)]
 
 mod block;

zebra-network/src/lib.rs

@@ -39,7 +39,13 @@
 // https://github.com/tokio-rs/tracing/issues/553
 #![allow(clippy::cognitive_complexity)]
 // Disable some broken or unwanted clippy nightly lints
+// Build without warnings on nightly 2021-01-17 and later and stable 1.51 and later
+#![allow(unknown_lints)]
+// Disable old lint warnings on nightly until 1.51 is stable
+#![allow(renamed_and_removed_lints)]
+// Use the old lint name to build without warnings on stable until 1.51 is stable
 #![allow(clippy::unknown_clippy_lints)]
+// The actual lints we want to disable
 #![allow(clippy::unnecessary_wraps)]
 
 #[macro_use]

zebra-script/src/lib.rs

@@ -3,7 +3,13 @@
 #![doc(html_logo_url = "https://www.zfnd.org/images/zebra-icon.png")]
 #![doc(html_root_url = "https://doc.zebra.zfnd.org/zebra_script")]
 // Disable some broken or unwanted clippy nightly lints
+// Build without warnings on nightly 2021-01-17 and later and stable 1.51 and later
+#![allow(unknown_lints)]
+// Disable old lint warnings on nightly until 1.51 is stable
+#![allow(renamed_and_removed_lints)]
+// Use the old lint name to build without warnings on stable until 1.51 is stable
 #![allow(clippy::unknown_clippy_lints)]
+// The actual lints we want to disable
 #![allow(clippy::unnecessary_wraps)]
 
 use displaydoc::Display;

zebra-state/src/lib.rs

@@ -6,7 +6,13 @@
 #![warn(missing_docs)]
 #![allow(clippy::try_err)]
 // Disable some broken or unwanted clippy nightly lints
+// Build without warnings on nightly 2021-01-17 and later and stable 1.51 and later
+#![allow(unknown_lints)]
+// Disable old lint warnings on nightly until 1.51 is stable
+#![allow(renamed_and_removed_lints)]
+// Use the old lint name to build without warnings on stable until 1.51 is stable
 #![allow(clippy::unknown_clippy_lints)]
+// The actual lints we want to disable
 #![allow(clippy::field_reassign_with_default)]
 #![allow(clippy::unnecessary_wraps)]
 

zebra-test/src/lib.rs

@@ -1,10 +1,16 @@
 //! Miscellaneous test code for Zebra.
 
-// Disable some broken or unwanted clippy nightly lints
-#![allow(clippy::unknown_clippy_lints)]
-#![allow(clippy::from_iter_instead_of_collect)]
 // Each lazy_static variable uses additional recursion
 #![recursion_limit = "256"]
+// Disable some broken or unwanted clippy nightly lints
+// Build without warnings on nightly 2021-01-17 and later and stable 1.51 and later
+#![allow(unknown_lints)]
+// Disable old lint warnings on nightly until 1.51 is stable
+#![allow(renamed_and_removed_lints)]
+// Use the old lint name to build without warnings on stable until 1.51 is stable
+#![allow(clippy::unknown_clippy_lints)]
+// The actual lints we want to disable
+#![allow(clippy::from_iter_instead_of_collect)]
 
 use color_eyre::section::PanicMessage;
 use owo_colors::OwoColorize;

zebrad/tests/acceptance.rs

@@ -16,7 +16,13 @@
 #![allow(dead_code)]
 #![allow(clippy::try_err)]
 // Disable some broken or unwanted clippy nightly lints
+// Build without warnings on nightly 2021-01-17 and later and stable 1.51 and later
+#![allow(unknown_lints)]
+// Disable old lint warnings on nightly until 1.51 is stable
+#![allow(renamed_and_removed_lints)]
+// Use the old lint name to build without warnings on stable until 1.51 is stable
 #![allow(clippy::unknown_clippy_lints)]
+// The actual lints we want to disable
 #![allow(clippy::field_reassign_with_default)]
 
 use color_eyre::eyre::Result;