fix: let the build continue to rustc on cbindgen failures

silently remove autopush.h instead just in case cbindgen fails when rustc
doesn't (to indicate something went wrong)

Closes #1235

autopush_rs/build.rs

@@ -1,16 +1,26 @@
 //! Generate autopush.h via cbindgen
 extern crate cbindgen;
 
-use std::env;
+use std::{env, fs, path::PathBuf};
 
 fn main() {
     let crate_dir = env::var("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR undefined");
     let pkg_name = env::var("CARGO_PKG_NAME").expect("CARGO_PKG_NAME undefined");
-    let target = format!("{}/target/{}.h", crate_dir, pkg_name);
-    cbindgen::Builder::new()
+    let target = PathBuf::from(format!("{}/target/{}.h", crate_dir, pkg_name));
+
+    let result = cbindgen::Builder::new()
         .with_crate(crate_dir)
         .with_language(cbindgen::Language::C)
-        .generate()
-        .expect("cbindgen unable to generate bindings")
-        .write_to_file(target.as_str());
+        .generate();
+    match result {
+        Ok(bindings) => {
+            bindings.write_to_file(target);
+        }
+        Err(e) => {
+            eprintln!("cbindgen unable to generate bindings: {}", e);
+            if target.exists() {
+                fs::remove_file(target).unwrap();
+            }
+        }
+    }
 }