Index: doc/meson.build
--- doc/meson.build.orig
+++ doc/meson.build
@@ -19,7 +19,7 @@ if get_option('html_manual')
       'conf.py',
     ],
     command: [sphinx, '-q', '-b', 'html', '-d', '@OUTDIR@/doctrees', meson.current_source_dir(), '@OUTPUT@'],
-    build_by_default: true,
+    build_by_default: false,
     install: true,
     install_dir: join_paths(get_option('datadir'), 'doc', meson.project_name()),
   )