_emerge.depgraph._show_circular_deps(): Display only the smallest cycle

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index f4d2514786e951247e6fac146c37bd6b2849b2e1..2e2508baf8259b1fe907355f484b07d9a87b2022 100644 (file)
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -4110,6 +4110,15 @@ class depgraph(object):
                        if not root_nodes:
                                break
                        mygraph.difference_update(root_nodes)
+               
+               shortest_cycle = None
+               for cycle in mygraph.get_cycles(ignore_priority=DepPrioritySatisfiedRange.ignore_medium_soft):
+                       if not shortest_cycle or len(shortest_cycle) > len(cycle):
+                               shortest_cycle = cycle
+
+               if shortest_cycle:
+                       mygraph.difference_update(set(mygraph.order) - set(shortest_cycle))
+                       
                # Display the USE flags that are enabled on nodes that are part
                # of dependency cycles in case that helps the user decide to
                # disable some of them.
@@ -4134,7 +4143,28 @@ class depgraph(object):
                portage.writemsg(prefix + "Error: circular dependencies:\n",
                        noiselevel=-1)
                portage.writemsg("\n", noiselevel=-1)
-               mygraph.debug_print()
+
+               if shortest_cycle:
+                       indent = ""
+                       for id, pkg in enumerate(shortest_cycle):
+                               parent = None
+                               if id > 0:
+                                       parent = shortest_cycle[id-1]
+
+                               if parent:
+                                       priorities = mygraph.nodes[parent][0][pkg]
+                                       writemsg(indent + "%s (%s)\n" % (pkg, priorities[-1],), noiselevel=-1)
+                               else:
+                                       writemsg(indent + str(pkg) + " depends on\n", noiselevel=-1)
+                               indent += " "
+
+                       pkg = shortest_cycle[0]
+                       parent = shortest_cycle[-1]
+                       priorities = mygraph.nodes[parent][0][pkg]
+                       writemsg(indent + "%s (%s)\n" % (pkg, priorities[-1],), noiselevel=-1)
+               else:
+                       mygraph.debug_print()
+
                portage.writemsg("\n", noiselevel=-1)
                portage.writemsg(prefix + "Note that circular dependencies " + \
                        "can often be avoided by temporarily\n", noiselevel=-1)