diff --git a/.github/workflows/conda-package-build.yml b/.github/workflows/conda-package-build.yml
index 7cf8b7f..23eafef 100644
--- a/.github/workflows/conda-package-build.yml
+++ b/.github/workflows/conda-package-build.yml
@@ -55,10 +55,10 @@ jobs:
         if_true: 'true'
         if_false: 'false'
     - name: Build and Publish
-      uses: openalea/action-build-publish-anaconda@v0.1.3
+      uses: openalea/action-build-publish-anaconda@v0.1.4
       with:
         conda: conda
-        mamba: true
+        mamba: false
         python: ${{ matrix.python-minor-version }}
         numpy: '20.0'
         channels: openalea3, conda-forge
diff --git a/src/openalea/weberpenn/mtg_client.py b/src/openalea/weberpenn/mtg_client.py
index df31ae2..dd1c42e 100644
--- a/src/openalea/weberpenn/mtg_client.py
+++ b/src/openalea/weberpenn/mtg_client.py
@@ -268,7 +268,7 @@ def plot(self):
 
         root = next(g.roots_iter(scale=2))
 
-        min_length = min([f.length for f in frames.values() if
+        min_length = min([f.length for f in list(frames.values()) if
                           f.length and f.length > 0])
         for vid in pre_order_turtle(g, root, p):
             down = frames[vid].down
@@ -333,7 +333,7 @@ def create_mtg_with_axes(g):
 
     edge_type = g.property('edge_type')
     colors[2] = g.vertices(scale=max_scale)
-    colors[1] = [vid for vid, edge in edge_type.items() if
+    colors[1] = [vid for vid, edge in list(edge_type.items()) if
                  edge == '+' and g.scale(vid) == max_scale]
     colors[1].insert(0, tree_root)
 
diff --git a/src/openalea/weberpenn/tree_geom.py b/src/openalea/weberpenn/tree_geom.py
index ac7bdf9..81c53e5 100644
--- a/src/openalea/weberpenn/tree_geom.py
+++ b/src/openalea/weberpenn/tree_geom.py
@@ -118,7 +118,7 @@ def leaves(self, color=green):
         leaves = server.leaves()
         leaf = self.leaf
         # map( lambda x: scene.add(self.leaf_shape(x,color,leaf)), leaves )
-        new_leaves = [self.leaf_shape(x, color, leaf) for leaf in leaves]
+        new_leaves = [self.leaf_shape(l, color, leaf) for l in leaves]
         self._shapes.extend(new_leaves)
 
     def leaf_shape(self, leaf, color, shape):
diff --git a/src/openalea/weberpenn/wralea/trunk_parameters.py b/src/openalea/weberpenn/wralea/trunk_parameters.py
index cc77616..1cb0e87 100644
--- a/src/openalea/weberpenn/wralea/trunk_parameters.py
+++ b/src/openalea/weberpenn/wralea/trunk_parameters.py
@@ -27,7 +27,7 @@ def __init__(self):
         
         Node.__init__(self)
 
-        shape_ids= self.shapes.keys()
+        shape_ids= list(self.shapes.keys())
         shape_ids.sort()
         
         inputs=[ {'interface': IEnumStr(shape_ids), 'name': 'shape_id', 'value': '0 - Conical'}, 
@@ -48,21 +48,22 @@ def __init__(self):
         self.add_output(name='trunk_params')
 
 
-    def __call__(self, (shape_id, 
-                       base_size, 
-                       scale, 
-                       scale_variance, 
-                       order, 
-                       ratio, 
-                       ratio_power, 
-                       leaves, 
-                       leaf_scale, 
-                       leaf_scale_x, 
-                       lobes, 
-                       lobes_variance, 
-                       flare, 
-                       base_split)):
+    def __call__(self, params):
         "Build trunk and global parameters."
+        (shape_id, 
+         base_size, 
+         scale, 
+         scale_variance, 
+         order, 
+         ratio, 
+         ratio_power, 
+         leaves, 
+         leaf_scale, 
+         leaf_scale_x, 
+         lobes, 
+         lobes_variance, 
+         flare, 
+         base_split) = params
         shape_id = self.shapes[shape_id]
         
         return dict((('shape_id', shape_id), 
@@ -178,13 +179,17 @@ class Species(Node):
 
     def __init__( self ):
         Node.__init__(self)
-        _species = self.trees.keys()
+        _species = list(self.trees.keys())
         _species.sort()
         
-        self.add_input(name='species', interface=IEnumStr(_species), value = 'Black Tupelo' )
+        self.add_input(
+            name='species', 
+            interface=IEnumStr(_species), 
+            value = 'Black Tupelo' )
         self.add_output(name='trunk_params')
         
-    def __call__( self, (t,) ):
+    def __call__( self, params ):
+        t, = params
         if t:
             return self.trees[t](),