Use once_cell to lower MSRV

Cargo.toml

@@ -20,6 +20,7 @@ collapsible_if = "allow"
 boxcar = "0.2.6"
 indexmap = "2.6.0"
 itertools = "0.13.0"
+once_cell = "1.20.2"
 pep440_rs = { version = "0.7.2", features = ["version-ranges"] }
 regex = "1.10.4"
 rustc-hash = "2.0.0"

src/marker/algebra.rs

@@ -51,17 +51,17 @@ use std::sync::Mutex;
 use std::sync::MutexGuard;
 
 use itertools::Either;
+use once_cell::sync::Lazy;
 use pep440_rs::{release_specifier_to_range, Operator, Version, VersionSpecifier};
 use rustc_hash::FxHashMap;
-use std::sync::LazyLock;
 use version_ranges::Ranges;
 
 use crate::marker::MarkerValueExtra;
 use crate::ExtraOperator;
 use crate::{MarkerExpression, MarkerOperator, MarkerValueString, MarkerValueVersion};
 
 /// The global node interner.
-pub(crate) static INTERNER: LazyLock<Interner> = LazyLock::new(Interner::default);
+pub(crate) static INTERNER: Lazy<Interner> = Lazy::new(Interner::default);
 
 /// An interner for decision nodes.
 ///

src/marker/tree.rs

@@ -1344,7 +1344,7 @@ pub struct MarkerTreeDebugGraph<'a> {
     marker: &'a MarkerTree,
 }
 
-impl<'a> fmt::Debug for MarkerTreeDebugGraph<'a> {
+impl fmt::Debug for MarkerTreeDebugGraph<'_> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.marker.fmt_graph(f, 0)
     }
@@ -1361,7 +1361,7 @@ pub struct MarkerTreeDebugRaw<'a> {
     marker: &'a MarkerTree,
 }
 
-impl<'a> fmt::Debug for MarkerTreeDebugRaw<'a> {
+impl fmt::Debug for MarkerTreeDebugRaw<'_> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let node = INTERNER.shared.node(self.marker.0);
         f.debug_tuple("MarkerTreeDebugRaw").field(node).finish()

src/verbatim_url.rs

@@ -1,11 +1,11 @@
+use once_cell::sync::Lazy;
 use regex::Regex;
 use std::borrow::Cow;
 use std::cmp::Ordering;
 use std::fmt::Debug;
 use std::hash::Hash;
 use std::ops::Deref;
 use std::path::{Path, PathBuf};
-use std::sync::LazyLock;
 use thiserror::Error;
 use url::{ParseError, Url};
 
@@ -325,13 +325,13 @@ pub enum VerbatimUrlError {
 pub fn expand_env_vars(s: &str) -> Cow<'_, str> {
     // Generate the project root, to be used via the `${PROJECT_ROOT}`
     // environment variable.
-    static PROJECT_ROOT_FRAGMENT: LazyLock<String> = LazyLock::new(|| {
+    static PROJECT_ROOT_FRAGMENT: Lazy<String> = Lazy::new(|| {
         let project_root = std::env::current_dir().unwrap();
         project_root.to_string_lossy().to_string()
     });
 
-    static RE: LazyLock<Regex> =
-        LazyLock::new(|| Regex::new(r"(?P<var>\$\{(?P<name>[A-Z0-9_]+)})").unwrap());
+    static RE: Lazy<Regex> =
+        Lazy::new(|| Regex::new(r"(?P<var>\$\{(?P<name>[A-Z0-9_]+)})").unwrap());
 
     RE.replace_all(s, |caps: &regex::Captures<'_>| {
         let name = caps.name("name").unwrap().as_str();