diff --git a/.github/workflows/run_long_integration_tests.yml b/.github/workflows/run_long_integration_tests.yml
index a230dfc..13f1198 100644
--- a/.github/workflows/run_long_integration_tests.yml
+++ b/.github/workflows/run_long_integration_tests.yml
@@ -22,7 +22,7 @@ jobs:
       - name: Build
         run: |
           export PYTHONPATH=.
-          python ./integration_tests/test_previous_builds_are_reproducible.py --selected-builds "a.1" "a.2" "a.3"
+          python ./integration_tests/test_previous_builds_are_reproducible.py --selected-builds "a.1" "a.2" "a.3" "a.4"
 
       - name: Save artifacts
         uses: actions/upload-artifact@v3
diff --git a/Dockerfile b/Dockerfile
index 518a6ec..66922b1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,7 @@
 FROM ubuntu:22.04
 
 # Constants
-ARG BUILDER_NAME="multiversx/sdk-rust-contract-builder:v4.2.0"
+ARG BUILDER_NAME="multiversx/sdk-rust-contract-builder:v4.2.1"
 ARG VERSION_RUST="nightly-2022-10-16"
 ARG VERSION_BINARYEN="version_105"
 ARG DOWNLOAD_URL_BINARYEN="https://github.com/WebAssembly/binaryen/releases/download/${VERSION_BINARYEN}/binaryen-${VERSION_BINARYEN}-x86_64-linux.tar.gz"
diff --git a/build_with_docker.py b/build_with_docker.py
index a6422ca..e56da1d 100644
--- a/build_with_docker.py
+++ b/build_with_docker.py
@@ -20,7 +20,7 @@ def main(cli_args: List[str]):
     parser.add_argument("--packaged-src", type=str, help="source code packaged in a JSON file")
     parser.add_argument("--contract", type=str)
     parser.add_argument("--output", type=str, default=Path(os.getcwd()) / "output")
-    parser.add_argument("--package-whole-project-src", type=bool, default=False, help="include all project files in *.source.json (default: %(default)s)")
+    parser.add_argument("--package-whole-project-src", action="store_true", default=False, help="include all project files in *.source.json (default: %(default)s)")
     parser.add_argument("--cargo-target-dir", help="deprecated parameter, not used anymore")
     parser.add_argument("--no-wasm-opt", action="store_true", default=False, help="do not optimize wasm files after the build (default: %(default)s)")
     parser.add_argument("--build-root", type=str, required=False, help="root path (within container) for the build (default: %(default)s)")
diff --git a/integration_tests/previous_builds.py b/integration_tests/previous_builds.py
index 3f0d14c..6106521 100644
--- a/integration_tests/previous_builds.py
+++ b/integration_tests/previous_builds.py
@@ -60,5 +60,20 @@ def __init__(self, name: str,
             "safe-price-view": "b5a657445ae74423c60210c88a6fa89b0bd4bdd00d5f06e788e14495bccc34c9"
         },
         docker_image="sdk-rust-contract-builder:next"
+    ),
+    PreviousBuild(
+        name="a.4",
+        project_archive_url="https://github.com/multiversx/mx-exchange-sc/archive/refs/heads/reproducible-v2.5.2-governance-merkle-tree.zip",
+        project_relative_path_in_archive="mx-exchange-sc-reproducible-v2.5.2-governance-merkle-tree",
+        packaged_src_url=None,
+        contract_name=None,
+        expected_code_hashes={
+            "lkmex-transfer": "49809df9f07839f965f8197721083cf403c3db969ddc47b5940b4ee8b464af92",
+            "router": "3257d57945736298c96aa23f99ea0fba3b6da01f9d2103d81230d05cff62cb5a",
+            "pair": "e9f117971963cb3c24b14e2a7698d48c170335af2f5c8167774c48c3c1c654e3",
+            "locked-token-wrapper": "1d317cfa2bbe22ea1f878f8a32f90712d49f68a01665b86657d36910b430522f",
+            "safe-price-view": "b5a657445ae74423c60210c88a6fa89b0bd4bdd00d5f06e788e14495bccc34c9"
+        },
+        docker_image="sdk-rust-contract-builder:next"
     )
 ]
diff --git a/multiversx_sdk_rust_contract_builder/main.py b/multiversx_sdk_rust_contract_builder/main.py
index ebd7c58..08d0dbe 100644
--- a/multiversx_sdk_rust_contract_builder/main.py
+++ b/multiversx_sdk_rust_contract_builder/main.py
@@ -52,6 +52,9 @@ def main(cli_args: List[str]):
         packaged = PackagedSourceCode.from_file(packaged_src_path)
         packaged.unwrap_to_filesystem(HARDCODED_UNWRAP_FOLDER)
 
+        if not specific_contract:
+            specific_contract = packaged.metadata.contract_name
+
     metadata = BuildMetadata.from_env()
 
     options = BuildOptions(