* Option `-B' to always show the output of builders, regardless of

  verbosity level.

3 files changed, 18 insertions, 0 deletions

diff --git a/doc/manual/nix-env.xml b/doc/manual/nix-env.xml
index 702faa621156..c73716381f4d 100644
--- a/doc/manual/nix-env.xml
+++ b/doc/manual/nix-env.xml
@@ -9,6 +9,8 @@
       <command>nix-env</command>
       <arg rep='repeat'><option>--verbose</option></arg>
       <arg rep='repeat'><option>-v</option></arg>
+      <arg><option>--build-output</option></arg>
+      <arg><option>-B</option></arg>
       <arg><option>--keep-failed</option></arg>
       <arg><option>-K</option></arg>
       <arg>
diff --git a/doc/manual/nix-store.xml b/doc/manual/nix-store.xml
index 479c1c3b09a5..8c6bcfe3737d 100644
--- a/doc/manual/nix-store.xml
+++ b/doc/manual/nix-store.xml
@@ -9,6 +9,8 @@
       <command>nix-store</command>
       <arg rep='repeat'><option>--verbose</option></arg>
       <arg rep='repeat'><option>-v</option></arg>
+      <arg><option>--build-output</option></arg>
+      <arg><option>-B</option></arg>
       <arg><option>--keep-failed</option></arg>
       <arg><option>-K</option></arg>
       <arg choice='plain'><replaceable>operation</replaceable></arg>
diff --git a/doc/manual/opt-verbose.xml b/doc/manual/opt-verbose.xml
index 3868acf30852..53fe07ae76b8 100644
--- a/doc/manual/opt-verbose.xml
+++ b/doc/manual/opt-verbose.xml
@@ -71,3 +71,17 @@
 
   </listitem>
 </varlistentry>
+
+<varlistentry>
+  <term><option>--build-output</option> / <option>-B</option></term>
+  <listitem>
+    <para>
+      Causes the output written by build actions to standard output
+      and standard error to be echoed to standard error, regardless of
+      verbosity level.  By default, it is only echoed at a verbosity
+      level of at least 4 (<quote>Debug</quote>), and is suppressed at
+      lower levels.  Note that it is always written to a log file in
+      <filename><replaceable>prefix</replaceable>/nix/var/log/nix</filename>.
+    </para>
+  </listitem>
+</varlistentry>