doebuild_environment: comment on bug #408817
diff --git a/pym/portage/package/ebuild/doebuild.py b/pym/portage/package/ebuild/doebuild.py
index 56de554..ffad456 100644
--- a/pym/portage/package/ebuild/doebuild.py
+++ b/pym/portage/package/ebuild/doebuild.py
@@ -183,6 +183,14 @@
if mysettings.mycpv is not None and \
mysettings.configdict["pkg"].get("PF") == mypv and \
"CATEGORY" in mysettings.configdict["pkg"]:
+ # Assume that PF is enough to assume that we've got
+ # the correct CATEGORY, though this is not really
+ # a solid assumption since it's possible (though
+ # unlikely) that two packages in different
+ # categories have the same PF. Callers should call
+ # setcpv or create a clean clone of a locked config
+ # instance in order to ensure that this assumption
+ # does not fail like in bug #408817.
cat = mysettings.configdict["pkg"]["CATEGORY"]
mycpv = mysettings.mycpv
elif os.path.basename(pkg_dir) in (mysplit[0], mypv):
