fix(@stdlib/_tools/pkgs/addons): require binding.gyp to detect a native add-on

lib/node_modules/@stdlib/_tools/pkgs/addons/lib/inspect.js

@@ -68,11 +68,36 @@ function inspect( files, clbk ) {
 		fpath = resolve( dir, 'src', 'Makefile' );
 
 		debug( 'Checking for add-on...' );
-		exists( fpath, onExists );
+		exists( fpath, onExistsMakefile );
 	}
 
 	/**
-	* Callback invoked upon testing if a file exists.
+	* Callback invoked upon testing if a `src/Makefile` exists.
+	*
+	* @private
+	* @param {(Error|null)} error - error object
+	* @param {boolean} bool - boolean indicating whether a file exists
+	* @returns {void}
+	*/
+	function onExistsMakefile( error, bool ) {
+		var gpath;
+		var j = i + 1;
+		if ( error ) {
+			debug( 'Encountered an error when testing for add-on: %s (%d of %d). Error: %s', files[ i ], j, total, error.message );
+			return done();
+		}
+		if ( !bool ) {
+			debug( 'Unable to detect add-on.' );
+			return done();
+		}
+		// A `src/Makefile` is also present in WebAssembly-only packages, so additionally require a `binding.gyp` file, which is what `node-gyp` needs to build a native add-on:
+		gpath = resolve( dirname( files[ i ] ), 'binding.gyp' );
+		debug( 'Checking for `binding.gyp`...' );
+		exists( gpath, onExists );
+	}
+
+	/**
+	* Callback invoked upon testing if a `binding.gyp` file exists.
 	*
 	* @private
 	* @param {(Error|null)} error - error object

lib/node_modules/@stdlib/_tools/pkgs/addons/lib/sync.js

@@ -84,7 +84,9 @@ function findAddons( options ) {
 	for ( i = 0; i < files.length; i++ ) {
 		dir = dirname( files[ i ] );
 		fpath = resolve( dir, 'src', 'Makefile' );
-		if ( exists( fpath ) ) {
+
+		// A `src/Makefile` is also present in WebAssembly-only packages, so additionally require a `binding.gyp` file, which is what `node-gyp` needs to build a native add-on:
+		if ( exists( fpath ) && exists( resolve( dir, 'binding.gyp' ) ) ) {
 			out.push( dir );
 		}
 	}