Fix failing docs build

build.rs

@@ -1,11 +1,9 @@
 fn main() {
     println!("cargo:rustc-check-cfg=cfg(doccfg)");
     if let Some(true) = version_check::supports_feature("doc_cfg") {
-        if let Some(true) = version_check::supports_feature("doc_auto_cfg") {
-            // `doc` is already generated by rustdoc on stable
-            // `docrs` is generated by docs.rs when building
-            // This enables local builds to have feature annotations when supported using `doccfg`
-            println!("cargo:rustc-cfg=doccfg");
-        }
+        // `doc` is already generated by rustdoc on stable
+        // `docrs` is generated by docs.rs when building
+        // This enables local builds to have feature annotations when supported using `doccfg`
+        println!("cargo:rustc-cfg=doccfg");
     }
 }

src/lib.rs

@@ -176,7 +176,6 @@ unsafe { free_in_c(ptr) }
 
 // Enable `cargo +nightly doc --all-features` to show all items and their feature requirements.
 // `doccfg` is set by the `build.rs` when supported (nightly)
-#![cfg_attr(doccfg, feature(doc_auto_cfg))]
 #![cfg_attr(doccfg, feature(doc_cfg))]
 #![no_std]