diff --git a/script/configure_dev b/script/configure_dev
index b9cc5505..03c93a3b 100755
--- a/script/configure_dev
+++ b/script/configure_dev
@@ -4,7 +4,8 @@ set -eux
 
 CMAKE_C_COMPILER=${CMAKE_C_COMPILER:-"gcc"}
 CMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER:-"g++"}
-CMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE:-"Release"}
+CMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE:-"Debug"}
+
 CMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX:-/usr/local}
 
 SCALUQ_USE_OMP=${SCALUQ_USE_OMP:-"ON"}
diff --git a/src/gate/merge_gate.cpp b/src/gate/merge_gate.cpp
index d273b6d2..b0bce934 100644
--- a/src/gate/merge_gate.cpp
+++ b/src/gate/merge_gate.cpp
@@ -20,10 +20,7 @@ std::pair<Gate<Fp>, Fp> merge_gate_dense_matrix(const Gate<Fp>& gate1, const Gat
                                                  gate2->target_qubit_list(),
                                                  gate2->control_qubit_mask() & ~common_control_mask,
                                                  merged_operand_vector);
-    std::cerr << matrix1 << std::endl;
-    std::cerr << matrix2 << std::endl;
     auto matrix = matrix2 * matrix1;
-    std::cerr << matrix << std::endl;
     return {gate::DenseMatrix<Fp>(
                 merged_operand_vector, matrix, internal::mask_to_vector(common_control_mask)),
             0.};
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index b91dd1a6..a0eaf17a 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -7,7 +7,6 @@ add_executable(scaluq_test EXCLUDE_FROM_ALL
     circuit/param_circuit_test.cpp
     gate/gate_test.cpp
     gate/batched_gate_test.cpp
-    # gate/merge_test.cpp
     gate/merge_test.cpp
     gate/param_gate_test.cpp
     operator/test_pauli_operator.cpp
diff --git a/tests/state/state_vector_test.cpp b/tests/state/state_vector_test.cpp
index ef3c0dc2..6f35e125 100644
--- a/tests/state/state_vector_test.cpp
+++ b/tests/state/state_vector_test.cpp
@@ -11,14 +11,14 @@ using namespace scaluq;
 
 TEST(StateVectorTest, HaarRandomStateNorm) {
     {
-        const int n_tries = 20;
+        const int n_tries = 6;
         for (int n = 1; n <= n_tries; n++) {
             const auto state = StateVector<double>::Haar_random_state(n);
             ASSERT_NEAR(state.get_squared_norm(), 1., eps<double>);
         }
     }
     {
-        const int n_tries = 20;
+        const int n_tries = 6;
         for (int n = 1; n <= n_tries; n++) {
             const auto state = StateVector<float>::Haar_random_state(n);
             ASSERT_NEAR(state.get_squared_norm(), 1., eps<float>);
@@ -27,7 +27,7 @@ TEST(StateVectorTest, HaarRandomStateNorm) {
 }
 
 TEST(StateVectorTest, OperationAtIndex) {
-    auto state = StateVector<double>::Haar_random_state(10);
+    auto state = StateVector<double>::Haar_random_state(6);
     for (std::uint64_t i = 0; i < state.dim(); ++i) {
         state.set_amplitude_at(i, 1);
         ASSERT_NEAR(state.get_amplitude_at(i).real(), 1., eps<double>);
@@ -73,7 +73,7 @@ TEST(StateVectorTest, ComputationalBasisState) {
 }
 
 TEST(StateVectorTest, HaarRandomStateSameSeed) {
-    const std::uint64_t n = 10, m = 5;
+    const std::uint64_t n = 6, m = 5;
     for (std::uint64_t i = 0; i < m; ++i) {
         StateVector state1(StateVector<double>::Haar_random_state(n, i)),
             state2(StateVector<double>::Haar_random_state(n, i));
@@ -82,7 +82,7 @@ TEST(StateVectorTest, HaarRandomStateSameSeed) {
 }
 
 TEST(StateVectorTest, HaarRandomStateWithoutSeed) {
-    const std::uint64_t n = 10, m = 5;
+    const std::uint64_t n = 6, m = 5;
     for (std::uint64_t i = 0; i < m; ++i) {
         StateVector state1(StateVector<double>::Haar_random_state(n)),
             state2(StateVector<double>::Haar_random_state(n));
@@ -91,7 +91,7 @@ TEST(StateVectorTest, HaarRandomStateWithoutSeed) {
 }
 
 TEST(StateVectorTest, AddState) {
-    const std::uint64_t n = 10;
+    const std::uint64_t n = 6;
     StateVector state1(StateVector<double>::Haar_random_state(n));
     StateVector state2(StateVector<double>::Haar_random_state(n));
     auto vec1 = state1.get_amplitudes();
@@ -108,7 +108,7 @@ TEST(StateVectorTest, AddState) {
 
 TEST(StateVectorTest, AddStateWithCoef) {
     const CComplex coef(2.5, 1.3);
-    const std::uint64_t n = 10;
+    const std::uint64_t n = 6;
     StateVector state1(StateVector<double>::Haar_random_state(n));
     StateVector state2(StateVector<double>::Haar_random_state(n));
     auto vec1 = state1.get_amplitudes();
@@ -125,7 +125,7 @@ TEST(StateVectorTest, AddStateWithCoef) {
 }
 
 TEST(StateVectorTest, MultiplyCoef) {
-    const std::uint64_t n = 10;
+    const std::uint64_t n = 6;
     const CComplex coef(0.5, 0.2);
 
     StateVector state(StateVector<double>::Haar_random_state(n));
@@ -141,7 +141,7 @@ TEST(StateVectorTest, MultiplyCoef) {
 }
 
 TEST(StateVectorTest, GetZeroProbability) {
-    const std::uint64_t n = 10;
+    const std::uint64_t n = 6;
     StateVector<double> state(n);
     state.set_computational_basis(1);
     for (std::uint64_t i = 2; i <= 10; ++i) {
@@ -213,7 +213,7 @@ TEST(StateVectorTest, GetMarginalProbability) {
 }
 
 TEST(StateVectorTest, SamplingSuperpositionState) {
-    const std::uint64_t n = 10;
+    const std::uint64_t n = 6;
     const std::uint64_t nshot = 65536;
     const std::uint64_t test_count = 10;
     std::uint64_t pass_count = 0;
@@ -248,7 +248,7 @@ TEST(StateVectorTest, SamplingSuperpositionState) {
 }
 
 TEST(StateVectorTest, SamplingComputationalBasis) {
-    const std::uint64_t n = 10;
+    const std::uint64_t n = 7;
     const std::uint64_t nshot = 1024;
     StateVector<double> state(n);
     state.set_computational_basis(100);
diff --git a/tests/util/util.hpp b/tests/util/util.hpp
index 4c1c9b08..775abd67 100644
--- a/tests/util/util.hpp
+++ b/tests/util/util.hpp
@@ -19,7 +19,7 @@ constexpr Fp eps_() {
     else if constexpr (std::is_same_v<Fp, float>)
         return 1e-4;
     else
-        static_assert(internal::lazy_false_v<void>, "unknown GateImpl");
+        static_assert(internal::lazy_false_v<Fp>, "unknown GateImpl");
 }
 template <std::floating_point Fp>
 constexpr Fp eps = eps_<Fp>();