diff --git a/src/libutil/error.cc b/src/libutil/error.cc
index 7d105d8b4..6b6b268a2 100644
--- a/src/libutil/error.cc
+++ b/src/libutil/error.cc
@@ -135,7 +135,7 @@ std::optional<LinesOfCode> getCodeLines(const ErrPos &errPos)
     }
 }
 
-// if nixCode contains lines of code, print them to the ostream, indicating the error column.
+// print lines of code to the ostream, indicating the error column.
 void printCodeLines(std::ostream &out,
     const string &prefix,
     const ErrPos &errPos,
diff --git a/src/libutil/tests/logging.cc b/src/libutil/tests/logging.cc
index 221b1be1b..a73c1f8d9 100644
--- a/src/libutil/tests/logging.cc
+++ b/src/libutil/tests/logging.cc
@@ -173,7 +173,7 @@ namespace nix {
             });
 
         auto str = testing::internal::GetCapturedStderr();
-        ASSERT_STREQ(str.c_str(), "\x1B[31;1merror:\x1B[0m\x1B[34;1m --- error name --- error-unit-test\x1B[0m\n\x1B[34;1mat: \x1B[33;1m(2:13)\x1B[34;1m from command line argument\x1B[0m\n\nerror with code lines\n\n     1| previous line of code\n     2| this is the problem line of code\n      |             \x1B[31;1m^\x1B[0m\n     3| next line of code\n\nthis hint has \x1B[33;1myellow\x1B[0m templated \x1B[33;1mvalues\x1B[0m!!\n");
+        ASSERT_STREQ(str.c_str(), "\x1B[31;1merror:\x1B[0m\x1B[34;1m --- error name --- error-unit-test\x1B[0m\n\x1B[34;1mat: \x1B[33;1m(2:13)\x1B[34;1m from string\x1B[0m\n\nerror with code lines\n\n     1| previous line of code\n     2| this is the problem line of code\n      |             \x1B[31;1m^\x1B[0m\n     3| next line of code\n\nthis hint has \x1B[33;1myellow\x1B[0m templated \x1B[33;1mvalues\x1B[0m!!\n");
     }
 
     TEST(logError, logErrorWithInvalidFile) {
@@ -251,7 +251,6 @@ namespace nix {
 
     TEST(addTrace, showTracesWithShowTrace) {
         SymbolTable testTable;
-        // ErrorInfo::showTrace = true;
         auto problem_file = testTable.create(test_file);
 
         auto oneliner_file = testTable.create(one_liner);
@@ -267,15 +266,16 @@ namespace nix {
 
         testing::internal::CaptureStderr();
 
+        logger->setShowTrace(true);
+
         logError(e.info());
 
         auto str = testing::internal::GetCapturedStderr();
-        ASSERT_STREQ(str.c_str(), "\x1B[31;1merror:\x1B[0m\x1B[34;1m --- AssertionError --- error-unit-test\x1B[0m\n\x1B[34;1mat: \x1B[33;1m(2:13)\x1B[34;1m from command line argument\x1B[0m\n\na well-known problem occurred\n\n     1| previous line of code\n     2| this is the problem line of code\n      |             \x1B[31;1m^\x1B[0m\n     3| next line of code\n\nit has been \x1B[33;1mzero\x1B[0m days since our last error\n\x1B[34;1m--- show-trace output ---\nwhile trying to compute \x1B[33;1m42\x1B[0m\n\x1B[34;1mat: \x1B[33;1m(1:19)\x1B[34;1m from stdin\x1B[0m\n     1| this is the other problem line of code\n      |                   \x1B[31;1m^\x1B[0m\n");
+        ASSERT_STREQ(str.c_str(), "\x1B[31;1merror:\x1B[0m\x1B[34;1m --- AssertionError --- error-unit-test\x1B[0m\n\x1B[34;1mat: \x1B[33;1m(2:13)\x1B[34;1m from string\x1B[0m\n\na well-known problem occurred\n\n     1| previous line of code\n     2| this is the problem line of code\n      |             \x1B[31;1m^\x1B[0m\n     3| next line of code\n\nit has been \x1B[33;1mzero\x1B[0m days since our last error\n\x1B[34;1m---- show-trace ----\x1B[0m\n\x1B[34;1mtrace: \x1B[0mwhile trying to compute \x1B[33;1m42\x1B[0m\n\x1B[34;1mat: \x1B[33;1m(1:19)\x1B[34;1m from stdin\x1B[0m\n\n     1| this is the other problem line of code\n      |                   \x1B[31;1m^\x1B[0m\n\n");
     }
 
     TEST(addTrace, hideTracesWithoutShowTrace) {
         SymbolTable testTable;
-        // ErrorInfo::showTrace = false;
         auto problem_file = testTable.create(test_file);
 
         auto oneliner_file = testTable.create(one_liner);
@@ -291,10 +291,12 @@ namespace nix {
 
         testing::internal::CaptureStderr();
 
+        logger->setShowTrace(false);
+
         logError(e.info());
 
         auto str = testing::internal::GetCapturedStderr();
-        ASSERT_STREQ(str.c_str(), "\x1B[31;1merror:\x1B[0m\x1B[34;1m --- AssertionError --- error-unit-test\x1B[0m\n\x1B[34;1mat: \x1B[33;1m(2:13)\x1B[34;1m from command line argument\x1B[0m\n\na well-known problem occurred\n\n     1| previous line of code\n     2| this is the problem line of code\n      |             \x1B[31;1m^\x1B[0m\n     3| next line of code\n\nit has been \x1B[33;1mzero\x1B[0m days since our last error\n");
+        ASSERT_STREQ(str.c_str(), "\x1B[31;1merror:\x1B[0m\x1B[34;1m --- AssertionError --- error-unit-test\x1B[0m\n\x1B[34;1mat: \x1B[33;1m(2:13)\x1B[34;1m from string\x1B[0m\n\na well-known problem occurred\n\n     1| previous line of code\n     2| this is the problem line of code\n      |             \x1B[31;1m^\x1B[0m\n     3| next line of code\n\nit has been \x1B[33;1mzero\x1B[0m days since our last error\n");
     }
 
     /* ----------------------------------------------------------------------------