diff --git a/Makefile b/Makefile
index 032d7ae2..ab1fcb89 100644
--- a/Makefile
+++ b/Makefile
@@ -148,7 +148,7 @@ endif
 ifdef DEBUG_HARDHAT
   TEST_PARAMS := $(TEST_PARAMS) -d:DebugHardhat=$(DEBUG_HARDHAT)
 endif
-ifdef DEBUG_CODEXNODES
+ifdef DEBUG_CODEXNODES # true by default
   TEST_PARAMS := $(TEST_PARAMS) -d:DebugCodexNodes=$(DEBUG_CODEXNODES)
 endif
 ifdef DEBUG_UPDATES
diff --git a/build.nims b/build.nims
index aa090e71..9ff8c5ce 100644
--- a/build.nims
+++ b/build.nims
@@ -1,10 +1,14 @@
 mode = ScriptMode.Verbose
 
 import std/os except commandLineParams
+import std/strutils
 
 ### Helper functions
-proc buildBinary(name: string, srcDir = "./", params = "", lang = "c") =
+proc truthy(val: string): bool =
+  const truthySwitches = @["yes", "1", "on", "true"]
+  return val in truthySwitches
 
+proc buildBinary(name: string, srcDir = "./", params = "", lang = "c") =
   if not dirExists "build":
     mkDir "build"
 
@@ -14,13 +18,15 @@ proc buildBinary(name: string, srcDir = "./", params = "", lang = "c") =
     for param in commandLineParams():
       extra_params &= " " & param
   else:
-    for i in 2..<paramCount():
+    for i in 2 ..< paramCount():
       extra_params &= " " & paramStr(i)
 
   let
     # Place build output in 'build' folder, even if name includes a longer path.
     outName = os.lastPathPart(name)
-    cmd = "nim " & lang & " --out:build/" & outName & " " & extra_params & " " & srcDir & name & ".nim"
+    cmd =
+      "nim " & lang & " --out:build/" & outName & " " & extra_params & " " & srcDir &
+      name & ".nim"
 
   exec(cmd)
 
@@ -29,7 +35,8 @@ proc test(name: string, srcDir = "tests/", params = "", lang = "c") =
   exec "build/" & name
 
 task codex, "build codex binary":
-  buildBinary "codex", params = "-d:chronicles_runtime_filtering -d:chronicles_log_level=TRACE"
+  buildBinary "codex",
+    params = "-d:chronicles_runtime_filtering -d:chronicles_log_level=TRACE"
 
 task toolsCirdl, "build tools/cirdl binary":
   buildBinary "tools/cirdl/cirdl"
@@ -41,8 +48,14 @@ task testContracts, "Build & run Codex Contract tests":
   test "testContracts"
 
 task testIntegration, "Run integration tests":
-  buildBinary "codex", params = "-d:chronicles_runtime_filtering -d:chronicles_log_level=TRACE -d:codex_enable_proof_failures=true"
-  test "testIntegration"
+  buildBinary "codex",
+    params =
+      "-d:chronicles_runtime_filtering -d:chronicles_log_level=TRACE -d:codex_enable_proof_failures=true"
+  var testParams = ""
+  for i in 2 ..< paramCount():
+    if "DebugTestHarness" in paramStr(i) and truthy paramStr(i).split('=')[1]:
+      testParams = "-d:chronicles_log_level=TRACE -d:chronicles_sinks=textlines[stdout]"
+  test "testIntegration", params = testParams
   # use params to enable logging from the integration test executable
   # test "testIntegration", params = "-d:chronicles_sinks=textlines[notimestamps,stdout],textlines[dynamic] " &
   #   "-d:chronicles_enabled_topics:integration:TRACE"  
@@ -90,15 +103,25 @@ task coverage, "generates code coverage report":
 
   var nimSrcs = " "
   for f in walkDirRec("codex", {pcFile}):
-    if f.endswith(".nim"): nimSrcs.add " " & f.absolutePath.quoteShell()
+    if f.endswith(".nim"):
+      nimSrcs.add " " & f.absolutePath.quoteShell()
 
   echo "======== Running Tests ======== "
-  test "coverage", srcDir = "tests/", params = " --nimcache:nimcache/coverage -d:release -d:codex_enable_proof_failures=true"
+  test "coverage",
+    srcDir = "tests/",
+    params =
+      " --nimcache:nimcache/coverage -d:release -d:codex_enable_proof_failures=true"
   exec("rm nimcache/coverage/*.c")
-  rmDir("coverage"); mkDir("coverage")
+  rmDir("coverage")
+  mkDir("coverage")
   echo " ======== Running LCOV ======== "
-  exec("lcov --capture --directory nimcache/coverage --output-file coverage/coverage.info")
-  exec("lcov --extract coverage/coverage.info --output-file coverage/coverage.f.info " & nimSrcs)
+  exec(
+    "lcov --capture --directory nimcache/coverage --output-file coverage/coverage.info"
+  )
+  exec(
+    "lcov --extract coverage/coverage.info --output-file coverage/coverage.f.info " &
+      nimSrcs
+  )
   echo " ======== Generating HTML coverage report ======== "
   exec("genhtml coverage/coverage.f.info --output-directory coverage/report ")
   echo " ======== Coverage report Done ======== "