* The default verbosity level of all Nix commands is now lvlInfo.

* Builder output is written to standard error by default.
  * The option `-B' is gone.
  * The option `-Q' suppresses builder output.

The result of this is that most Nix invocations shouldn't need any
flags w.r.t. logging.

doc/manual/opt-common-syn.xml

@@ -2,8 +2,8 @@
 <arg><option>--version</option></arg>
 <arg rep='repeat'><option>--verbose</option></arg>
 <arg rep='repeat'><option>-v</option></arg>
-<arg><option>--build-output</option></arg>
+<arg><option>--no-build-output</option></arg>
-<arg><option>-B</option></arg>
+<arg><option>-Q</option></arg>
 <arg>
   <group choice='req'>
     <arg choice='plain'><option>--max-jobs</option></arg>

doc/manual/opt-common.xml

@@ -50,7 +50,7 @@
           <para>
             <quote>Informational</quote>: print
             <emphasis>useful</emphasis> messages about what Nix is
-            doing.
+            doing.  This is the default.
           </para>
         </listitem>
       </varlistentry>
@@ -94,14 +94,13 @@
 
 
 <varlistentry>
-  <term><option>--build-output</option> / <option>-B</option></term>
+  <term><option>--no-build-output</option> / <option>-Q</option></term>
   <listitem>
     <para>
-      Causes the output written by build actions to standard output
+      By default, output written by builders to standard output and
-      and standard error to be echoed to standard error, regardless of
+      standard error is echoed to the Nix command's standard error.
-      verbosity level.  By default, it is only echoed at a verbosity
+      This option suppresses this behaviour.  Note that the builder's
-      level of at least 4 (<quote>Debug</quote>), and is suppressed at
+      standard output and error are always written to a log file in
-      lower levels.  Note that it is always written to a log file in
       <filename><replaceable>prefix</replaceable>/nix/var/log/nix</filename>.
     </para>
   </listitem>

src/libmain/shared.cc

@@ -126,7 +126,9 @@ static void initAndRun(int argc, char * * argv)
             setLogType(*i);
         }
         else if (arg == "--build-output" || arg == "-B")
-            buildVerbosity = lvlError; /* lowest */
+            ; /* !!! obsolete - remove eventually */
+        else if (arg == "--no-build-output" || arg == "-Q")
+            buildVerbosity = lvlVomit;
         else if (arg == "--help") {
             printHelp();
             return;

src/libstore/globals.cc

@@ -12,6 +12,6 @@ bool keepGoing = false;
 
 bool tryFallback = false;
 
-Verbosity buildVerbosity = lvlDebug;
+Verbosity buildVerbosity = lvlInfo;
 
 unsigned int maxBuildJobs = 1;

src/libutil/util.cc

@@ -243,7 +243,7 @@ void writeStringToFile(const Path & path, const string & s)
 
 
 LogType logType = ltPretty;
-Verbosity verbosity = lvlError;
+Verbosity verbosity = lvlInfo;
 
 static int nestingLevel = 0;
 

src/nix-env/main.cc

@@ -704,9 +704,6 @@ static void opDefaultExpr(Globals & globals,
 
 void run(Strings args)
 {
-    /* Use a higher default verbosity (lvlInfo). */
-    verbosity = (Verbosity) ((int) verbosity + 1);
-
     Strings opFlags, opArgs;
     Operation op = 0;