3 files changed, 26 insertions, 28 deletions

diff --git a/src/libutil/logging.cc b/src/libutil/logging.cc
index 7a58527b8..90c6afe81 100644
--- a/src/libutil/logging.cc
+++ b/src/libutil/logging.cc
@@ -1,5 +1,6 @@
 #include "logging.hh"
 #include "util.hh"
+#include "config.hh"
 
 #include <atomic>
 #include <nlohmann/json.hpp>
@@ -7,6 +8,10 @@
 
 namespace nix {
 
+LoggerSettings loggerSettings;
+
+static GlobalConfig::Register r1(&loggerSettings);
+
 static thread_local ActivityId curActivity = 0;
 
 ActivityId getCurActivity()
@@ -18,7 +23,7 @@ void setCurActivity(const ActivityId activityId)
     curActivity = activityId;
 }
 
-Logger * logger = makeSimpleLogger(true, false);
+Logger * logger = makeSimpleLogger(true);
 
 void Logger::warn(const std::string & msg)
 {
@@ -36,10 +41,9 @@ public:
 
     bool systemd, tty;
     bool printBuildLogs;
-    bool showTrace;
 
-    SimpleLogger(bool printBuildLogs, bool showTrace)
-        : printBuildLogs(printBuildLogs), showTrace(showTrace)
+    SimpleLogger(bool printBuildLogs)
+        : printBuildLogs(printBuildLogs)
     {
         systemd = getEnv("IN_SYSTEMD") == "1";
         tty = isatty(STDERR_FILENO);
@@ -49,13 +53,6 @@ public:
         return printBuildLogs;
     }
 
-    bool getShowTrace() const override {
-        return showTrace;
-    }
-    void setShowTrace(bool showTrace) override {
-        this->showTrace = showTrace;
-    }
-
     void log(Verbosity lvl, const FormatOrString & fs) override
     {
         if (lvl > verbosity) return;
@@ -80,7 +77,7 @@ public:
     void logEI(const ErrorInfo & ei) override
     {
         std::stringstream oss;
-        showErrorInfo(oss, ei, showTrace);
+        showErrorInfo(oss, ei, loggerSettings.showTrace.get());
 
         log(ei.level, oss.str());
     }
@@ -129,9 +126,9 @@ void writeToStderr(const string & s)
     }
 }
 
-Logger * makeSimpleLogger(bool printBuildLogs, bool showTrace)
+Logger * makeSimpleLogger(bool printBuildLogs)
 {
-    return new SimpleLogger(printBuildLogs, showTrace);
+    return new SimpleLogger(printBuildLogs);
 }
 
 std::atomic<uint64_t> nextId{(uint64_t) getpid() << 32};
@@ -152,13 +149,6 @@ struct JSONLogger : Logger {
         return true;
     }
 
-    bool getShowTrace() const override {
-        return prevLogger.getShowTrace();
-    }
-    void setShowTrace(bool showTrace) override {
-        prevLogger.setShowTrace(showTrace);
-    }
-
     void addFields(nlohmann::json & json, const Fields & fields)
     {
         if (fields.empty()) return;
@@ -189,7 +179,7 @@ struct JSONLogger : Logger {
     void logEI(const ErrorInfo & ei) override
     {
         std::ostringstream oss;
-        showErrorInfo(oss, ei, getShowTrace());
+        showErrorInfo(oss, ei, loggerSettings.showTrace.get());
 
         nlohmann::json json;
         json["action"] = "msg";
diff --git a/src/libutil/logging.hh b/src/libutil/logging.hh
index 273300b50..09619aac6 100644
--- a/src/libutil/logging.hh
+++ b/src/libutil/logging.hh
@@ -2,6 +2,7 @@
 
 #include "types.hh"
 #include "error.hh"
+#include "config.hh"
 
 namespace nix {
 
@@ -34,6 +35,16 @@ typedef enum {
 
 typedef uint64_t ActivityId;
 
+struct LoggerSettings : Config
+{
+    Setting<bool> showTrace{this,
+        false,
+        "show-trace",
+        "Whether to show a stack trace on evaluation errors."};
+};
+
+extern LoggerSettings loggerSettings;
+
 class Logger
 {
     friend struct Activity;
@@ -75,9 +86,6 @@ public:
         logEI(ei);
     }
 
-    virtual bool getShowTrace() const = 0;
-    virtual void setShowTrace(bool showTrace) = 0;
-
     virtual void warn(const std::string & msg);
 
     virtual void startActivity(ActivityId act, Verbosity lvl, ActivityType type,
@@ -149,7 +157,7 @@ struct PushActivity
 
 extern Logger * logger;
 
-Logger * makeSimpleLogger(bool printBuildLogs = true, bool showTrace = false);
+Logger * makeSimpleLogger(bool printBuildLogs = true);
 
 Logger * makeJSONLogger(Logger & prevLogger);
 
diff --git a/src/libutil/tests/logging.cc b/src/libutil/tests/logging.cc
index f51e40fa8..ef22e9966 100644
--- a/src/libutil/tests/logging.cc
+++ b/src/libutil/tests/logging.cc
@@ -266,7 +266,7 @@ namespace nix {
 
         testing::internal::CaptureStderr();
 
-        logger->setShowTrace(true);
+        loggerSettings.showTrace.assign(true);
 
         logError(e.info());
 
@@ -292,7 +292,7 @@ namespace nix {
 
         testing::internal::CaptureStderr();
 
-        logger->setShowTrace(false);
+        loggerSettings.showTrace.assign(false);
 
         logError(e.info());