fixup! chore(ffi): avoid hardcoding clang version

Address review comments

bindings/matrix-sdk-crypto-ffi/build.rs

@@ -1,5 +1,4 @@
 use std::{env, error::Error};
-use std::ffi::OsStr;
 use std::path::PathBuf;
 use std::process::Command;
 use vergen::EmitBuilder;
@@ -17,24 +16,27 @@ fn setup_x86_64_android_workaround() {
         // Configure rust to statically link against the `libclang_rt.builtins` supplied with clang.
 
         // cargo-ndk sets CC_x86_64-linux-android to the path to `clang`, within the Android NDK.
-        let cc = PathBuf::from(env::var("CC_x86_64-linux-android").expect("CC_x86_64-linux-android not set"));
+        let clang_path = PathBuf::from(env::var("CC_x86_64-linux-android").expect("CC_x86_64-linux-android not set"));
 
-        let toolchain_path = cc
+        // clang_path should now look something like
+        // `.../sdk/ndk/28.0.12674087/toolchains/llvm/prebuilt/linux-x86_64/bin/clang`.
+        // We strip `/bin/clang` from the end to get the toolchain path.
+        let toolchain_path = clang_path
             .ancestors()
             .nth(2)
             .expect("could not find NDK toolchain path")
             .to_str()
             .expect("NDK toolchain path is not valid UTF-8");
 
-        let clang_version = get_clang_major_version(&cc);
+        let clang_version = get_clang_major_version(&clang_path);
 
         println!("cargo:rustc-link-search={toolchain_path}/lib/clang/{clang_version}/lib/linux/");
         println!("cargo:rustc-link-lib=static=clang_rt.builtins-x86_64-android");
     }
 }
 
 /// Run the clang binary at `clang_path`, and return its major version number
-fn get_clang_major_version(clang_path: impl AsRef<OsStr>) -> String {
+fn get_clang_major_version(clang_path: &PathBuf) -> String {
     let clang_output = Command::new(clang_path)
         .arg("-dumpversion")
         .output()

bindings/matrix-sdk-ffi/build.rs

@@ -1,5 +1,4 @@
 use std::{env, error::Error};
-use std::ffi::OsStr;
 use std::path::PathBuf;
 use std::process::Command;
 use vergen::EmitBuilder;
@@ -17,24 +16,27 @@ fn setup_x86_64_android_workaround() {
         // Configure rust to statically link against the `libclang_rt.builtins` supplied with clang.
 
         // cargo-ndk sets CC_x86_64-linux-android to the path to `clang`, within the Android NDK.
-        let cc = PathBuf::from(env::var("CC_x86_64-linux-android").expect("CC_x86_64-linux-android not set"));
+        let clang_path = PathBuf::from(env::var("CC_x86_64-linux-android").expect("CC_x86_64-linux-android not set"));
 
-        let toolchain_path = cc
+        // clang_path should now look something like
+        // `.../sdk/ndk/28.0.12674087/toolchains/llvm/prebuilt/linux-x86_64/bin/clang`.
+        // We strip `/bin/clang` from the end to get the toolchain path.
+        let toolchain_path = clang_path
             .ancestors()
             .nth(2)
             .expect("could not find NDK toolchain path")
             .to_str()
             .expect("NDK toolchain path is not valid UTF-8");
 
-        let clang_version = get_clang_major_version(&cc);
+        let clang_version = get_clang_major_version(&clang_path);
 
         println!("cargo:rustc-link-search={toolchain_path}/lib/clang/{clang_version}/lib/linux/");
         println!("cargo:rustc-link-lib=static=clang_rt.builtins-x86_64-android");
     }
 }
 
 /// Run the clang binary at `clang_path`, and return its major version number
-fn get_clang_major_version(clang_path: impl AsRef<OsStr>) -> String {
+fn get_clang_major_version(clang_path: &PathBuf) -> String {
     let clang_output = Command::new(clang_path)
         .arg("-dumpversion")
         .output()