chrono replaced with time, local_offset feature flag added (#110)

* removed chrono for time, put local_offset support behind a feature flag

* docs update

* cargo fmt

Cargo.toml

@@ -13,29 +13,31 @@ repository = "https://github.com/rustyhorde/vergen"
 version = "6.0.2"
 
 [package.metadata.cargo-all-features]
-denylist = ["chrono","git2","rustc_version","sysinfo"]
+denylist = ["local_offset","time","git2","rustc_version","sysinfo"]
 
 [features]
 default = ["build", "cargo", "git", "rustc", "si"]
-build = ["chrono"]
+build = ["time"]
 cargo = []
-git = ["chrono", "git2"]
+git = ["time", "git2"]
 rustc = ["rustc_version"]
 si = ["sysinfo"]
+local_offset = ["time/local-offset"]
 
 [dependencies]
 anyhow = "1"
 cfg-if = "1"
-chrono = { version = "0", optional = true, default-features = false }
 enum-iterator = "0"
 getset = "0"
 git2 = { version = "0", optional = true, default-features = false }
 rustc_version = { version = "0.4.0", optional = true }
 sysinfo = { version = "=0.23", optional = true, default-features = false }
 thiserror = "1"
+time = { version = "0.3.7", optional = true }
 
 [build-dependencies]
-chrono = "0"
+anyhow = "1.0.56"
+time = { version = "0.3.7", features = ["formatting"] }
 rustversion = "1"
 
 [dev-dependencies]

README.md

@@ -5,6 +5,13 @@ Generate `build`, `git`, `rustc`, `cargo`, and `sysinfo` related [`cargo:rustc-e
 Special thanks to the sponsors of this project
 * [tyretool](https://github.com/tryretool)
 
+## Release 7.0 Breaking Changes
+* `chrono` has been replaced with `time`. The `time` crate is better maintained.
+* The local timezone support in the `build` and `git` features has been moved behind a `local_offset` feature flag.  This is
+due to a [potential segfault](https://github.com/rustsec/advisory-db/blob/main/crates/time/RUSTSEC-2020-0071.md) when using `localtime_r` as the `time` crate does.
+* To build with the `local_offset` feature, you must also explicitly delare that you are acknowledging the potential unsoundness by
+setting `RUSTFLAGS="--cfg unsound_local_offset"`.  Per the `time` docs this isn't tested, so use with extreme caution.
+
 ## Release 6.0 Breaking Changes
 * The `Copy` implementation was dropped from the [`Config`](https://github.com/rustyhorde/vergen/blob/24ed6bc2269320ab98962edc8b736fcc6e3c7d64/src/config.rs#L94-L148) struct to allow the base git directory to be specified.  This is a breaking API change necessitating a new major release.
 ## Current Release

build.rs

@@ -1,18 +1,20 @@
-use chrono::Utc;
+use anyhow::Result;
+use time::{format_description::well_known::Rfc3339, OffsetDateTime};
 
-pub fn main() {
+pub fn main() -> Result<()> {
     println!("cargo:rerun-if-changed=build.rs");
     // These are here so some doc tests work
-    let now = Utc::now();
+    let now = OffsetDateTime::now_utc();
     println!(
         "cargo:rustc-env=VERGEN_BUILD_TIMESTAMP={}",
-        now.to_rfc3339()
+        now.format(&Rfc3339)?
     );
     println!("cargo:rustc-env=VERGEN_GIT_SEMVER=v3.2.0-86-g95fc0f5");
     nightly_lints();
     beta_lints();
     stable_lints();
     msrv_lints();
+    Ok(())
 }
 
 #[rustversion::nightly]

src/config.rs

@@ -52,7 +52,11 @@ use std::{
 ///
 /// ```
 /// use vergen::Config;
-#[cfg_attr(feature = "git", doc = r##"use vergen::TimeZone;"##)]
+#[cfg_attr(feature = "git", doc = r##"use vergen::ShaKind;"##)]
+#[cfg_attr(
+    all(feature = "git", feature = "local_offset"),
+    doc = r##"use vergen::TimeZone;"##
+)]
 ///
 /// let mut config = Config::default();
 #[cfg_attr(
@@ -65,7 +69,15 @@ use std::{
 #[cfg_attr(
     feature = "git",
     doc = r##"
-// Change the commit timestamp timezone to local
+// Change the SHA output to the short variant
+*config.git_mut().sha_kind_mut() = ShaKind::Short;
+"##
+)]
+#[cfg_attr(
+    all(feature = "git", feature = "local_offset"),
+    doc = r##"
+// Change the SHA output to the short variant
+*config.git_mut().sha_kind_mut() = ShaKind::Short;
 *config.git_mut().commit_timestamp_timezone_mut() = TimeZone::Local;
 "##
 )]
@@ -137,7 +149,7 @@ impl Instructions {
     {
         let mut config = Config::default();
 
-        configure_build(&self, &mut config);
+        configure_build(&self, &mut config)?;
         configure_git(&self, repo_path, &mut config)?;
         configure_rustc(&self, &mut config)?;
         configure_cargo(&self, &mut config);

src/feature/build.rs

@@ -9,15 +9,16 @@
 //! `vergen` build feature implementation
 
 use crate::config::{Config, Instructions};
+use anyhow::Result;
 #[cfg(feature = "build")]
 use {
     crate::{
         config::VergenKey,
         feature::{add_entry, TimeZone, TimestampKind},
     },
-    chrono::{DateTime, Local, Utc},
     getset::{Getters, MutGetters},
     std::env,
+    time::{format_description, OffsetDateTime},
 };
 
 /// Configuration for the `VERGEN_BUILD_*` instructions
@@ -42,7 +43,11 @@ use {
 /// ```
 /// # use anyhow::Result;
 /// use vergen::{vergen, Config};
-#[cfg_attr(feature = "build", doc = r##"use vergen::{TimestampKind, TimeZone};"##)]
+#[cfg_attr(feature = "build", doc = r##"use vergen::TimestampKind;"##)]
+#[cfg_attr(
+    all(feature = "build", feature = "local_offset"),
+    doc = r##"use vergen::TimeZone;"##
+)]
 ///
 /// # pub fn main() -> Result<()> {
 /// let mut config = Config::default();
@@ -51,7 +56,17 @@ use {
     doc = r##"
 // Generate all three date/time instructions
 *config.build_mut().kind_mut() = TimestampKind::All;
-// Change the date/time instructions to show `Local` time
+
+// Generate the instructions
+vergen(config)?;
+"##
+)]
+#[cfg_attr(
+    all(feature = "build", feature = "local_offset"),
+    doc = r##"
+// Generate all three date/time instructions
+*config.build_mut().kind_mut() = TimestampKind::All;
+// Generate the output time in the local timezone
 *config.build_mut().timezone_mut() = TimeZone::Local;
 
 // Generate the instructions
@@ -97,14 +112,19 @@ impl Build {
 }
 
 #[cfg(feature = "build")]
-pub(crate) fn configure_build(instructions: &Instructions, config: &mut Config) {
+pub(crate) fn configure_build(instructions: &Instructions, config: &mut Config) -> Result<()> {
     let build_config = instructions.build();
 
     if build_config.has_enabled() {
         if *build_config.timestamp() {
             match build_config.timezone() {
-                TimeZone::Utc => add_config_entries(config, *build_config, &Utc::now()),
-                TimeZone::Local => add_config_entries(config, *build_config, &Local::now()),
+                TimeZone::Utc => {
+                    add_config_entries(config, *build_config, &OffsetDateTime::now_utc())?;
+                }
+                #[cfg(feature = "local_offset")]
+                TimeZone::Local => {
+                    add_config_entries(config, *build_config, &OffsetDateTime::now_local()?)?;
+                }
             };
         }
 
@@ -116,71 +136,70 @@ pub(crate) fn configure_build(instructions: &Instructions, config: &mut Config)
             );
         }
     }
+    Ok(())
 }
 
 #[cfg(feature = "build")]
-fn add_config_entries<T>(config: &mut Config, build_config: Build, now: &DateTime<T>)
-where
-    T: chrono::TimeZone,
-    T::Offset: std::fmt::Display,
-{
+fn add_config_entries(
+    config: &mut Config,
+    build_config: Build,
+    now: &OffsetDateTime,
+) -> Result<()> {
     match build_config.kind() {
-        TimestampKind::DateOnly => add_date_entry(config, now),
-        TimestampKind::TimeOnly => add_time_entry(config, now),
+        TimestampKind::DateOnly => add_date_entry(config, now)?,
+        TimestampKind::TimeOnly => add_time_entry(config, now)?,
         TimestampKind::DateAndTime => {
-            add_date_entry(config, now);
-            add_time_entry(config, now);
+            add_date_entry(config, now)?;
+            add_time_entry(config, now)?;
         }
-        TimestampKind::Timestamp => add_timestamp_entry(config, now),
+        TimestampKind::Timestamp => add_timestamp_entry(config, now)?,
         TimestampKind::All => {
-            add_date_entry(config, now);
-            add_time_entry(config, now);
-            add_timestamp_entry(config, now);
+            add_date_entry(config, now)?;
+            add_time_entry(config, now)?;
+            add_timestamp_entry(config, now)?;
         }
     }
+    Ok(())
 }
 
 #[cfg(feature = "build")]
-fn add_date_entry<T>(config: &mut Config, now: &DateTime<T>)
-where
-    T: chrono::TimeZone,
-    T::Offset: std::fmt::Display,
-{
+fn add_date_entry(config: &mut Config, now: &OffsetDateTime) -> Result<()> {
+    let format = format_description::parse("[year]-[month]-[day]")?;
     add_entry(
         config.cfg_map_mut(),
         VergenKey::BuildDate,
-        Some(now.format("%Y-%m-%d").to_string()),
+        Some(now.format(&format)?),
     );
+    Ok(())
 }
 
 #[cfg(feature = "build")]
-fn add_time_entry<T>(config: &mut Config, now: &DateTime<T>)
-where
-    T: chrono::TimeZone,
-    T::Offset: std::fmt::Display,
-{
+fn add_time_entry(config: &mut Config, now: &OffsetDateTime) -> Result<()> {
+    let format = format_description::parse("[hour]:[minute]:[second]")?;
     add_entry(
         config.cfg_map_mut(),
         VergenKey::BuildTime,
-        Some(now.format("%H:%M:%S").to_string()),
+        Some(now.format(&format)?),
     );
+    Ok(())
 }
 
 #[cfg(feature = "build")]
-fn add_timestamp_entry<T>(config: &mut Config, now: &DateTime<T>)
-where
-    T: chrono::TimeZone,
-    T::Offset: std::fmt::Display,
-{
+fn add_timestamp_entry(config: &mut Config, now: &OffsetDateTime) -> Result<()> {
+    use time::format_description::well_known::Rfc3339;
+
     add_entry(
         config.cfg_map_mut(),
         VergenKey::BuildTimestamp,
-        Some(now.to_rfc3339()),
+        Some(now.format(&Rfc3339)?),
     );
+    Ok(())
 }
 
 #[cfg(not(feature = "build"))]
-pub(crate) fn configure_build(_instructions: &Instructions, _config: &mut Config) {}
+pub(crate) fn configure_build(_instructions: &Instructions, _config: &mut Config) -> Result<()> {
+    Ok(())
+}
 
 #[cfg(all(test, feature = "build"))]
 mod test {