Docs: add a docstring for UserDef.pythondir

1 files changed, 15 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_userdef_types.h b/source/blender/makesdna/DNA_userdef_types.h
index e6e2b6553c0..d304641e112 100644
--- a/source/blender/makesdna/DNA_userdef_types.h
+++ b/source/blender/makesdna/DNA_userdef_types.h
@@ -673,6 +673,21 @@ typedef struct UserDef {
   /** 768 = FILE_MAXDIR. */
   char render_cachedir[768];
   char textudir[768];
+  /**
+   * Optional user location for scripts.
+   *
+   * This supports the same layout as Blender's scripts directory `release/scripts`.
+   *
+   * \note Unlike most paths, changing this is not fully supported at run-time,
+   * requiring a restart to properly take effect. Supporting this would cause complications as
+   * the script path can contain `startup`, `addons` & `modules` etc. properly unwinding the
+   * Python environment to the state it _would_ have been in gets complicated.
+   *
+   * Although this is partially supported as the `sys.path` is refreshed when loading preferences.
+   * This is done to support #PREFERENCES_OT_copy_prev which is available to the user when they
+   * launch with a new version of Blender. In this case setting the script path on top of
+   * factory settings will work without problems.
+   */
   char pythondir[768];
   char sounddir[768];
   char i18ndir[768];