Make tracing optional

Cargo.toml

@@ -18,7 +18,7 @@ lazy_static = "1.4.0"
 pyo3 = { version = "0.18.3", optional = true, features = ["extension-module", "abi3-py37"] }
 regex = { version = "1.8.1", default-features = false, features = ["std", "perf", "unicode-case", "unicode-perl"] }
 serde = { version = "1.0.162", features = ["derive"], optional = true }
-tracing = "0.1.37"
+tracing = { version = "0.1.37", optional = true }
 unicode-width = "0.1.10"
 
 [dev-dependencies]

src/version.rs

@@ -15,6 +15,8 @@ use std::fmt::{Display, Formatter};
 use std::hash::{Hash, Hasher};
 use std::iter;
 use std::str::FromStr;
+
+#[cfg(feature = "tracing")]
 use tracing::warn;
 
 /// A regex copied from <https://peps.python.org/pep-0440/#appendix-b-parsing-version-strings-with-regular-expressions>,
@@ -97,7 +99,10 @@ impl FromStr for Operator {
  let operator = match s {
  "==" => Self::Equal,
  "===" => {
- warn!("Using arbitrary equality (`===`) is discouraged");
+ #[cfg(feature = "tracing")]
+ {
+ warn!("Using arbitrary equality (`===`) is discouraged");
+ }
  #[allow(deprecated)]
  Self::ExactEqual
  }

src/version_specifier.rs

@@ -22,9 +22,11 @@ use std::fmt::{Debug, Display};
 use std::hash::{Hash, Hasher};
 use std::ops::Deref;
 use std::str::FromStr;
-use tracing::warn;
 use unicode_width::UnicodeWidthStr;
 
+#[cfg(feature = "tracing")]
+use tracing::warn;
+
 lazy_static! {
  /// Matches a python version specifier, such as `>=1.19.a1` or `4.1.*`. Extends the PEP 440
  /// version regex to version specifiers
@@ -384,7 +386,10 @@ impl VersionSpecifier {
  }
  #[allow(deprecated)]
  Operator::ExactEqual => {
- warn!("Using arbitrary equality (`===`) is discouraged");
+ #[cfg(feature = "tracing")]
+ {
+ warn!("Using arbitrary equality (`===`) is discouraged");
+ }
  self.version.to_string() == version.to_string()
  }
  Operator::NotEqual => other != this,