211 lines
6.6 KiB
XML
211 lines
6.6 KiB
XML
<sect1 id="sec-common-options"><title>Common options</title>
|
||
|
||
<para>Most Nix commands accept the following command-line options:</para>
|
||
|
||
<variablelist>
|
||
|
||
<varlistentry><term><option>--help</option></term>
|
||
|
||
<listitem><para>Prints out a summary of the command syntax and
|
||
exits.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
|
||
<varlistentry><term><option>--version</option></term>
|
||
|
||
<listitem><para>Prints out the Nix version number on standard output
|
||
and exits.</para></listitem>
|
||
</varlistentry>
|
||
|
||
|
||
<varlistentry><term><option>--verbose</option> / <option>-v</option></term>
|
||
|
||
<listitem>
|
||
|
||
<para>Increases the level of verbosity of diagnostic messages
|
||
printed on standard error. For each Nix operation, the information
|
||
printed on standard output is well-defined; any diagnostic
|
||
information is printed on standard error, never on standard
|
||
output.</para>
|
||
|
||
<para>This option may be specified repeatedly. Currently, the
|
||
following verbosity levels exist:</para>
|
||
|
||
<variablelist>
|
||
|
||
<varlistentry><term>0</term>
|
||
<listitem><para>“Errors only”: only print messages
|
||
explaining why the Nix invocation failed.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry><term>1</term>
|
||
<listitem><para>“Informational”: print
|
||
<emphasis>useful</emphasis> messages about what Nix is doing.
|
||
This is the default.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry><term>2</term>
|
||
<listitem><para>“Talkative”: print more informational
|
||
messages.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry><term>3</term>
|
||
<listitem><para>“Chatty”: print even more
|
||
informational messages.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry><term>4</term>
|
||
<listitem><para>“Debug”: print debug
|
||
information.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry><term>5</term>
|
||
<listitem><para>“Vomit”: print vast amounts of debug
|
||
information.</para></listitem>
|
||
</varlistentry>
|
||
|
||
</variablelist>
|
||
|
||
</listitem>
|
||
|
||
</varlistentry>
|
||
|
||
|
||
<varlistentry><term><option>--no-build-output</option> / <option>-Q</option></term>
|
||
|
||
<listitem><para>By default, output written by builders to standard
|
||
output and standard error is echoed to the Nix command's standard
|
||
error. This option suppresses this behaviour. Note that the
|
||
builder's standard output and error are always written to a log file
|
||
in
|
||
<filename><replaceable>prefix</replaceable>/nix/var/log/nix</filename>.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
|
||
<varlistentry id="opt-max-jobs"><term><option>--max-jobs</option> / <option>-j</option></term>
|
||
|
||
<listitem><para>Sets the maximum number of build jobs that Nix will
|
||
perform in parallel to the specified number. The default is 1. A
|
||
higher value is useful on SMP systems or to exploit I/O latency.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
|
||
<varlistentry><term><option>--keep-going</option> / <option>-k</option></term>
|
||
|
||
<listitem><para>Keep going in case of failed builds, to the
|
||
greatest extent possible. That is, if building an input of some
|
||
derivation fails, Nix will still build the other inputs, but not the
|
||
derivation itself. Without this option, Nix stops if any build
|
||
fails (except for builds of substitutes), possibly killing builds in
|
||
progress (in case of parallel or distributed builds).</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
|
||
<varlistentry><term><option>--keep-failed</option> / <option>-K</option></term>
|
||
|
||
<listitem><para>Specifies that in case of a build failure, the
|
||
temporary directory (usually in <filename>/tmp</filename>) in which
|
||
the build takes place should not be deleted. The path of the build
|
||
directory is printed as an informational message.
|
||
</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
|
||
<varlistentry><term><option>--fallback</option></term>
|
||
|
||
<listitem>
|
||
|
||
<para>Whenever Nix attempts to build a derivation for which
|
||
substitutes are known for each output path, but realising the output
|
||
paths through the substitutes fails, fall back on building the
|
||
derivation.</para>
|
||
|
||
<para>The most common scenario in which this is useful is when we
|
||
have registered substitutes in order to perform binary distribution
|
||
from, say, a network repository. If the repository is down, the
|
||
realisation of the derivation will fail. When this option is
|
||
specified, Nix will build the derivation instead. Thus,
|
||
installation from binaries falls back on nstallation from source.
|
||
This option is not the default since it is generally not desirable
|
||
for a transient failure in obtaining the substitutes to lead to a
|
||
full build from source (with the related consumption of
|
||
resources).</para>
|
||
|
||
</listitem>
|
||
|
||
</varlistentry>
|
||
|
||
|
||
<varlistentry><term><option>--readonly-mode</option></term>
|
||
|
||
<listitem><para>When this option is used, no attempt is made to open
|
||
the Nix database. Most Nix operations do need database access, so
|
||
those operations will fail.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
|
||
<varlistentry id="opt-log-type"><term><option>--log-type</option>
|
||
<replaceable>type</replaceable></term>
|
||
|
||
<listitem>
|
||
|
||
<para>This option determines how the output written to standard
|
||
error is formatted. Nix’s diagnostic messages are typically
|
||
<emphasis>nested</emphasis>. For instance, when tracing Nix
|
||
expression evaluation (<command>nix-env -vvvvv</command>, messages
|
||
from subexpressions are nested inside their parent expressions. Nix
|
||
builder output is also often nested. For instance, the Nix Packages
|
||
generic builder nests the various build tasks (unpack, configure,
|
||
compile, etc.), and the GNU Make in <literal>stdenv-linux</literal>
|
||
has been patched to provide nesting for recursive Make
|
||
invocations.</para>
|
||
|
||
<para><replaceable>type</replaceable> can be one of the
|
||
following:
|
||
|
||
<variablelist>
|
||
|
||
<varlistentry><term><literal>pretty</literal></term>
|
||
|
||
<listitem><para>Pretty-print the output, indicating different
|
||
nesting levels using spaces. This is the
|
||
default.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
<varlistentry><term><literal>escapes</literal></term>
|
||
|
||
<listitem><para>Indicate nesting using escape codes that can be
|
||
interpreted by the <command>log2xml</command> tool in the Nix
|
||
source distribution. The resulting XML file can be fed into the
|
||
<command>log2html.xsl</command> stylesheet to create an HTML
|
||
file that can be browsed interactively, using Javascript to
|
||
expand and collapse parts of the output.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
<varlistentry><term><literal>flat</literal></term>
|
||
|
||
<listitem><para>Remove all nesting.</para></listitem>
|
||
|
||
</varlistentry>
|
||
|
||
</variablelist>
|
||
|
||
</para>
|
||
|
||
</listitem>
|
||
|
||
</varlistentry>
|
||
|
||
|
||
</variablelist>
|
||
|
||
|
||
</sect1> |