fix: do not trust ctime by default.

On MacOS it seems to be off by two seconds right from the source, which
seems to be an issue `stat` isn't having.

Author: Byron

gix/src/config/cache/access.rs

@@ -158,7 +158,13 @@ impl Cache {
     pub(crate) fn stat_options(&self) -> Result<gix_index::entry::stat::Options, config::stat_options::Error> {
         use crate::config::tree::gitoxide;
         Ok(gix_index::entry::stat::Options {
-            trust_ctime: boolean(self, "core.trustCTime", &Core::TRUST_C_TIME, true)?,
+            trust_ctime: boolean(
+                self,
+                "core.trustCTime",
+                &Core::TRUST_C_TIME,
+                // For now, on MacOS it's known to not be trust-worthy at least with the Rust STDlib, being 2s off
+                !cfg!(target_os = "macos"),
+            )?,
             use_nsec: boolean(self, "gitoxide.core.useNsec", &gitoxide::Core::USE_NSEC, false)?,
             use_stdev: boolean(self, "gitoxide.core.useStdev", &gitoxide::Core::USE_STDEV, false)?,
             check_stat: self

gix/src/config/tree/sections/core.rs

@@ -45,7 +45,8 @@ impl Core {
     /// The `core.symlinks` key.
     pub const SYMLINKS: keys::Boolean = keys::Boolean::new_boolean("symlinks", &config::Tree::CORE);
     /// The `core.trustCTime` key.
-    pub const TRUST_C_TIME: keys::Boolean = keys::Boolean::new_boolean("trustCTime", &config::Tree::CORE);
+    pub const TRUST_C_TIME: keys::Boolean = keys::Boolean::new_boolean("trustCTime", &config::Tree::CORE)
+        .with_deviation("Currently the default is false, instead of true, as it seems to be 2s off in tests");
     /// The `core.worktree` key.
     pub const WORKTREE: keys::Any = keys::Any::new("worktree", &config::Tree::CORE)
         .with_environment_override("GIT_WORK_TREE")