From 7d892896e4f7e4fb44b1c8019386f9bba0504603 Mon Sep 17 00:00:00 2001
From: Arpan Chakraborty <chakrabortyarpan151@gmail.com>
Date: Wed, 20 May 2026 00:57:50 +0530
Subject: [PATCH 1/3] fix: support Colon() in middle of indices for NodeLabel
 getindex (#275)

---
 src/graph_engine.jl      |  1 +
 test/test_colon_index.jl | 17 +++++++++++++++++
 2 files changed, 18 insertions(+)
 create mode 100644 test/test_colon_index.jl

diff --git a/src/graph_engine.jl b/src/graph_engine.jl
index f9961354..d16a83af 100644
--- a/src/graph_engine.jl
+++ b/src/graph_engine.jl
@@ -254,6 +254,7 @@ end
 Base.length(label::NodeLabel) = 1
 Base.size(label::NodeLabel) = ()
 Base.getindex(label::NodeLabel, any) = label
+Base.getindex(label::NodeLabel, i1, is...) = label
 Base.:(<)(left::NodeLabel, right::NodeLabel) = left.global_counter < right.global_counter
 Base.broadcastable(label::NodeLabel) = Ref(label)
 
diff --git a/test/test_colon_index.jl b/test/test_colon_index.jl
new file mode 100644
index 00000000..4c98b4a8
--- /dev/null
+++ b/test/test_colon_index.jl
@@ -0,0 +1,17 @@
+using Test
+using GraphPPL
+using Distributions
+
+@model function test_colon_bug(media)
+    for g in 1:2
+        for i in 1:3
+            media_effect[g, i] := media[g, :, i]
+        end
+    end
+end
+
+@testset "Colon index in middle of indices" begin
+    media_data = rand(2, 5, 3)
+    model = create_model(test_colon_bug(media = media_data))
+    @test model !== nothing
+end

From e3a8bcb30f427b5c0910bd853d56600df5a44eb0 Mon Sep 17 00:00:00 2001
From: Arpan Chakraborty <chakrabortyarpan151@gmail.com>
Date: Wed, 20 May 2026 01:02:53 +0530
Subject: [PATCH 2/3] chore: add CHANGELOG entry for #303

---
 CHANGELOG.md | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 00000000..a785a7d6
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,8 @@
+\## \[Unreleased]
+
+
+
+\### Fixed
+
+\- Fixed `Colon()` not working in the middle of indices for `NodeLabel` getindex (\[#303](https://github.com/ReactiveBayes/GraphPPL.jl/pull/303))
+

From 7e030b1669456ae943cadb72e2c0870d09d6e687 Mon Sep 17 00:00:00 2001
From: Arpan Chakraborty <chakrabortyarpan151@gmail.com>
Date: Wed, 20 May 2026 01:06:46 +0530
Subject: [PATCH 3/3] fix: improve error message for invalid factorization
 constraint set (#293)

---
 .../variational_constraints/variational_constraints_engine.jl   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/plugins/variational_constraints/variational_constraints_engine.jl b/src/plugins/variational_constraints/variational_constraints_engine.jl
index 2bf81577..aa64413e 100644
--- a/src/plugins/variational_constraints/variational_constraints_engine.jl
+++ b/src/plugins/variational_constraints/variational_constraints_engine.jl
@@ -636,7 +636,7 @@ function materialize_constraints!(model::Model, node_label::NodeLabel, node_data
 
     if !is_valid_partition(constraint_set)
         error(
-            lazy"Factorization constraint set at node $node_label is not a valid constraint set. Please check your model definition and constraint specification. (Constraint set: $constraint_bitset)"
+            lazy"Factorization constraint set at node $node_label is not a valid constraint set. Please check your model definition and constraint specification. (Constraint set: $constraint_bitset)\n\nHint: A valid constraint set requires that each interface belongs to exactly one factorization group. In the constraint matrix, each column must have exactly one non-zero entry per group. Make sure all variables appearing in your model are included in your factorization constraint."
         )
     end