slot_abi_mask_built: don't discard other masks

diff --git a/pym/_emerge/resolver/backtracking.py b/pym/_emerge/resolver/backtracking.py
index 09df9c82256733361927b38b9d743d0fc2b3df95..f39bad4139ffc68325366c60b8a4e9d84c982820 100644 (file)
--- a/pym/_emerge/resolver/backtracking.py
+++ b/pym/_emerge/resolver/backtracking.py
@@ -187,7 +187,9 @@ class Backtracker(object):
                                for pkg, (new_use, new_changes) in data:
                                        para.needed_use_config_changes[pkg] = (new_use, new_changes)
                        elif change == "slot_abi_mask_built":
-                               para.runtime_pkg_mask.update(data)
+                               for pkg, mask_reasons in data.items():
+                                       para.runtime_pkg_mask.setdefault(pkg,
+                                               {}).update(mask_reasons)
                        elif change == "slot_abi_replace_installed":
                                para.slot_abi_replace_installed.update(data)
                        elif change == "rebuild_list":