See https://github.com/mesonbuild/meson-python/blob/main/mesonpy/__init__.py#L452.

(Also: https://github.com/mesonbuild/meson-python/issues/54)
--- a/mesonpy/__init__.py
+++ b/mesonpy/__init__.py
@@ -734,7 +734,7 @@ class Project():
     @functools.lru_cache(maxsize=None)
     def build(self) -> None:
         """Trigger the Meson build."""
-        self._meson('compile', *self._meson_args['compile'],)
+        self._meson('compile', '--verbose', *self._meson_args['compile'],)
         self._meson('install', '--destdir', os.fspath(self._install_dir), *self._meson_args['install'],)

     @classmethod