_prepare_self_update: detect if already called
This is should never be triggered by portage, but it's possible that
an API consumer might trigger it somehow.
diff --git a/pym/portage/package/ebuild/doebuild.py b/pym/portage/package/ebuild/doebuild.py
index 9e71cfc..4ba523c 100644
--- a/pym/portage/package/ebuild/doebuild.py
+++ b/pym/portage/package/ebuild/doebuild.py
@@ -2024,6 +2024,10 @@
automatically clean up the temporary copies.
"""
+ # sanity check: ensure that that this routine only runs once
+ if portage._bin_path != portage.const.PORTAGE_BIN_PATH:
+ return
+
# Load lazily referenced portage submodules into memory,
# so imports won't fail during portage upgrade/downgrade.
_preload_elog_modules(settings)
