fix(build): improve error messages when cmake is not found

Replace bare .unwrap() calls on cmake Command invocations with
descriptive error handling.

Author: jaoleal

libbitcoinkernel-sys/build.rs

@@ -17,7 +17,7 @@ fn main() {
 
     let build_config = "RelWithDebInfo";
 
-    Command::new("cmake")
+    let configure_status = Command::new("cmake")
         .arg("-B")
         .arg(&build_dir)
         .arg("-S")
@@ -42,29 +42,44 @@ fn main() {
         .arg("-DENABLE_IPC=OFF")
         .arg(format!("-DCMAKE_INSTALL_PREFIX={}", install_dir.display()))
         .status()
-        .unwrap();
+        .unwrap_or_else(|e| panic!("Failed to run cmake configure: {e}."));
+
+    if !configure_status.success() {
+        panic!("cmake configure failed (exit status: {configure_status}).");
+    }
 
     let num_jobs = env::var("NUM_JOBS")
         .ok()
         .and_then(|v| v.parse::<u32>().ok())
         .unwrap_or(1); // Default to 1 if not set
 
-    Command::new("cmake")
+    let build_status = Command::new("cmake")
         .arg("--build")
         .arg(&build_dir)
         .arg("--config")
         .arg(build_config)
         .arg(format!("--parallel={num_jobs}"))
         .status()
-        .unwrap();
+        .unwrap_or_else(|e| panic!("Failed to run cmake build: {e}."));
+
+    if !build_status.success() {
+        panic!(
+            "cmake build failed (exit status: {build_status}). Check the build output above for details. Build directory: '{}'",
+            build_dir.display()
+        );
+    }
 
-    Command::new("cmake")
+    let install_status = Command::new("cmake")
         .arg("--install")
         .arg(&build_dir)
         .arg("--config")
         .arg(build_config)
         .status()
-        .unwrap();
+        .unwrap_or_else(|e| panic!("Failed to run cmake install: {e}"));
+
+    if !install_status.success() {
+        panic!("cmake install failed (exit status: {install_status}).");
+    }
 
     // Check if the build system used a multi-config generator
     let lib_dir = if install_dir.join("lib").join(build_config).exists() {