Remove track_caller feature detection because msrv was bumped

Cargo.toml

@@ -66,10 +66,7 @@ generate-parsing-rs = ["peg"]
 testing-helpers = ["rustc_version"]
 is_variant = ["convert_case"]
 unwrap = ["convert_case", "rustc_version"]
-# Feature that requires post-MSRV Rust version,
-# of 1.46. We perform rustc version detection in the
-# build script for features that require this.
-# (Currently just `unwrap`.)
+# Unused, kept for backwards compatibility
 track-caller = []
 
 default = [

build.rs

@@ -34,20 +34,7 @@ fn detect_nightly() {
  }
 }
 
-#[cfg(not(feature = "unwrap"))]
-fn detect_track_caller() {}
-/// Detect availability of the `#[track_caller]` attribute for
-/// use in derived panicking methods like `.unwrap_*()`.
-#[cfg(feature = "unwrap")]
-fn detect_track_caller() {
- use rustc_version::version_meta;
- if version_meta().unwrap().semver.minor >= 46 {
- println!("cargo:rustc-cfg=feature=\"track-caller\"");
- }
-}
-
 fn main() {
  detect_nightly();
- detect_track_caller();
  generate_peg();
 }

src/unwrap.rs

@@ -71,16 +71,8 @@ pub fn expand(input: &DeriveInput, trait_name: &'static str) -> Result<TokenStre
  }
  });
 
- // The `track-caller` feature is set by our build script based
- // on rustc version detection, as `#[track_caller]` was
- // stabilized in a later version (1.46) of Rust than our MSRV (1.36).
- let track_caller = if cfg!(feature = "track-caller") {
- quote! { #[track_caller] }
- } else {
- quote! {}
- };
  let func = quote! {
- #track_caller
+ #[track_caller]
  pub fn #fn_name(self) -> #ret_type {
  match self {
  #enum_name ::#variant_ident #data_pattern => #ret_value,