diff --git a/contrib/ethereum/libethash/ethash.cpp b/contrib/ethereum/libethash/ethash.cpp
index f12faab7..10ee9c6d 100644
--- a/contrib/ethereum/libethash/ethash.cpp
+++ b/contrib/ethereum/libethash/ethash.cpp
@@ -145,7 +145,11 @@ epoch_context_full* create_epoch_context(
 
     char* const alloc_data = static_cast<char*>(std::calloc(1, alloc_size));
     if (!alloc_data)
-        return nullptr;  // Signal out-of-memory by returning null pointer.
+    {
+      LOG_CUSTOM_WITH_CALLSTACK("CRITICAL: std::calloc(" << alloc_size << ") failed in create_epoch_context()", 0);
+      return nullptr;  // Signal out-of-memory by returning null pointer.
+    }
+    LOG_CUSTOM("context for epoch " << epoch_number << " allocated, size: " << alloc_size << " bytes", 0);
 
     hash512* const light_cache = reinterpret_cast<hash512*>(alloc_data + context_alloc_size);
     const hash256 epoch_seed = calculate_epoch_seed(epoch_number);
@@ -373,6 +377,33 @@ search_result search(const epoch_context_full& context, const hash256& header_ha
     }
     return {};
 }
+
+custom_log_level_function*& access_custom_log_level_function()
+{
+  static custom_log_level_function* p_custom_log_level_function = nullptr;
+  return p_custom_log_level_function;
+}
+
+custom_log_function*& access_custom_log_function()
+{
+  static custom_log_function* p_custom_log_function = nullptr;
+  return p_custom_log_function;
+}
+
+int get_custom_log_level()
+{
+  if (access_custom_log_level_function() != nullptr)
+    return access_custom_log_level_function()();
+  return -1;
+}
+
+void custom_log(const std::string& m, bool add_callstack)
+{
+  if (access_custom_log_function() != nullptr)
+    access_custom_log_function()(m, add_callstack);
+}
+
+
 }  // namespace ethash
 
 using namespace ethash;
@@ -434,6 +465,8 @@ void ethash_destroy_epoch_context_full(epoch_context_full* context) noexcept
 
 void ethash_destroy_epoch_context(epoch_context* context) noexcept
 {
+    LOG_CUSTOM("context for epoch " << context->epoch_number << " is about to be freed", 0);
+
     context->~epoch_context();
     std::free(context);
 }
diff --git a/contrib/ethereum/libethash/ethash/ethash.hpp b/contrib/ethereum/libethash/ethash/ethash.hpp
index 8034090b..0f2962a5 100644
--- a/contrib/ethereum/libethash/ethash/ethash.hpp
+++ b/contrib/ethereum/libethash/ethash/ethash.hpp
@@ -20,6 +20,8 @@
 #include <cstdint>
 #include <cstring>
 #include <memory>
+#include <string>
+#include <sstream>
 
 namespace ethash
 {
@@ -157,4 +159,33 @@ const epoch_context& get_global_epoch_context(int epoch_number);
 
 /// Get global shared epoch context with full dataset initialized.
 std::shared_ptr<epoch_context_full> get_global_epoch_context_full(int epoch_number);
+
+typedef int (custom_log_level_function)();
+typedef void (custom_log_function)(const std::string& m, bool add_callstack);
+
+custom_log_level_function*& access_custom_log_level_function();
+custom_log_function*& access_custom_log_function();
+int get_custom_log_level();
+void custom_log(const std::string& m, bool add_callstack);
+
+#define LOG_CUSTOM(msg, level)                  \
+{                                               \
+  if (level <= ethash::get_custom_log_level())  \
+  {                                             \
+    std::stringstream ss;                       \
+    ss << msg << std::endl;                     \
+    ethash::custom_log(ss.str(), false);        \
+  }                                             \
+}
+
+#define LOG_CUSTOM_WITH_CALLSTACK(msg, level)   \
+{                                               \
+  if (level <= ethash::get_custom_log_level())  \
+  {                                             \
+    std::stringstream ss;                       \
+    ss << msg << std::endl;                     \
+    ethash::custom_log(ss.str(), true);         \
+  }                                             \
+}
+
 }  // namespace ethash
diff --git a/src/currency_core/basic_pow_helpers.cpp b/src/currency_core/basic_pow_helpers.cpp
index b97a1087..ddb87912 100644
--- a/src/currency_core/basic_pow_helpers.cpp
+++ b/src/currency_core/basic_pow_helpers.cpp
@@ -22,17 +22,31 @@ namespace currency
 {
 
   //--------------------------------------------------------------
-  //global object 
-//   crypto::ethash::cache_manager cache;
-//   void ethash_set_use_dag(bool use_dag)
-//   {
-//     cache.set_use_dag(use_dag);
-//   }
-//   //------------------------------------------------------------------
-//   const uint8_t* ethash_get_dag(uint64_t epoch, uint64_t& dag_size)
-//   {
-//     return cache.get_dag(epoch, dag_size);
-//   }
+  int ethash_custom_log_get_level()
+  {
+    return epee::log_space::get_set_log_detalisation_level();
+  }
+  //--------------------------------------------------------------
+  void ethash_custom_log(const std::string& m, bool add_callstack)
+  {
+    std::string msg = epee::log_space::log_singletone::get_prefix_entry() + "[ETHASH]" + m;
+    if (add_callstack)
+      msg = msg + "callstask: " + epee::misc_utils::get_callstack();
+
+    epee::log_space::log_singletone::do_log_message(msg, LOG_LEVEL_0, epee::log_space::console_color_default, true, LOG_DEFAULT_TARGET);
+  }
+  //--------------------------------------------------------------
+  void init_ethash_log_if_necessary()
+  {
+    static bool inited = false;
+    if (inited)
+      return;
+
+    ethash::access_custom_log_level_function() = &ethash_custom_log_get_level;
+    ethash::access_custom_log_function() = &ethash_custom_log;
+
+    inited = true;
+  }
   //------------------------------------------------------------------
   int ethash_height_to_epoch(uint64_t height)
   {
@@ -49,6 +63,7 @@ namespace currency
   //--------------------------------------------------------------
   crypto::hash get_block_longhash(uint64_t height, const crypto::hash& block_header_hash, uint64_t nonce)
   {
+    init_ethash_log_if_necessary();
     int epoch = ethash_height_to_epoch(height);
     std::shared_ptr<ethash::epoch_context_full> p_context = progpow::get_global_epoch_context_full(static_cast<int>(epoch));
     CHECK_AND_ASSERT_THROW_MES(p_context, "progpow::get_global_epoch_context_full returned null");
diff --git a/src/version.h.in b/src/version.h.in
index 307ec14d..d469b618 100644
--- a/src/version.h.in
+++ b/src/version.h.in
@@ -2,6 +2,6 @@
 
 #define BUILD_COMMIT_ID "@VERSION@"
 #define PROJECT_VERSION "1.0"
-#define PROJECT_VERSION_BUILD_NO 49
+#define PROJECT_VERSION_BUILD_NO 50
 #define PROJECT_VERSION_BUILD_NO_STR STRINGIFY_EXPAND(PROJECT_VERSION_BUILD_NO)
 #define PROJECT_VERSION_LONG PROJECT_VERSION "." PROJECT_VERSION_BUILD_NO_STR "[" BUILD_COMMIT_ID "]"