doebuild_environment: comment on bug #408817

diff --git a/pym/portage/package/ebuild/doebuild.py b/pym/portage/package/ebuild/doebuild.py
index 56de55441f06d581686e9a503bb5be9c6d529962..ffad4563f0278245bf7737b056f4c0e0709988bf 100644 (file)
--- a/pym/portage/package/ebuild/doebuild.py
+++ b/pym/portage/package/ebuild/doebuild.py
@@ -183,6 +183,14 @@ def doebuild_environment(myebuild, mydo, myroot=None, settings=None,
        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):