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authorEelco Dolstra <e.dolstra@tudelft.nl>2003-11-26T12·30+0000
committerEelco Dolstra <e.dolstra@tudelft.nl>2003-11-26T12·30+0000
commitf6a30ab264506ca966180666dff45310d176659d (patch)
tree147f661bb236e40bbe5c858b04117cb295b8ddf4 /doc/manual
parent2a4bac5459f42764b39ac70f906f5dd3330a3ac5 (diff)
* Updates.
Diffstat (limited to 'doc/manual')
-rw-r--r--doc/manual/book.xml2
-rw-r--r--doc/manual/bugs.xml39
-rw-r--r--doc/manual/installation.xml96
-rw-r--r--doc/manual/introduction.xml363
-rw-r--r--doc/manual/troubleshooting.xml21
5 files changed, 177 insertions, 344 deletions
diff --git a/doc/manual/book.xml b/doc/manual/book.xml
index 1dc69d0041a1..710246ca1bfa 100644
--- a/doc/manual/book.xml
+++ b/doc/manual/book.xml
@@ -12,7 +12,7 @@
 ]>
 
 <book>
-  <title>Nix: The Manual</title>
+  <title>Nix: A System for Software Deployment</title>
 
   <bookinfo>
     <author>
diff --git a/doc/manual/bugs.xml b/doc/manual/bugs.xml
index 548ce1cab830..fcb69c3641a5 100644
--- a/doc/manual/bugs.xml
+++ b/doc/manual/bugs.xml
@@ -1,34 +1,43 @@
 <appendix>
-  <title>Bugs</title>
+  <title>Bugs / To-Do</title>
 
   <itemizedlist>
 
     <listitem>
       <para>
-	Nix should automatically recover the Berkeley DB database.
+        Nix should automatically remove Berkeley DB logfiles.
       </para>
     </listitem>
 
     <listitem>
       <para>
-	Nix should automatically remove Berkeley DB logfiles.
+        Unify the concepts of successors and substitutes into a general notion
+        of <emphasis>equivalent expressions</emphasis>.  Expressions are
+        equivalent if they have the same target paths with the same
+        identifiers.  However, even though they are functionally equivalent,
+        they may differ stronly with respect to their <emphasis>performance
+          characteristics</emphasis>.  For example, realising a slice is more
+        efficient that realising the derivation from which that slice was
+        produced.  On the other hand, distributing sources may be more
+        efficient (storage- or bandwidth-wise) than distributing binaries.  So
+        we need to be able to attach weigths or priorities or performance
+        annotations to expressions; Nix can then choose the most efficient
+        expression dependent on the context.
       </para>
     </listitem>
 
     <listitem>
       <para>
-	Unify the concepts of successors and substitutes into a general notion
-	of <emphasis>equivalent expressions</emphasis>.  Expressions are
-	equivalent if they have the same target paths with the same
-	identifiers.  However, even though they are functionally equivalent,
-	they may differ stronly with respect to their <emphasis>performance
-	  characteristics</emphasis>.  For example, realising a slice is more
-	efficient that realising the derivation from which that slice was
-	produced.  On the other hand, distributing sources may be more
-	efficient (storage- or bandwidth-wise) than distributing binaries.  So
-	we need to be able to attach weigths or priorities or performance
-	annotations to expressions; Nix can then choose the most efficient
-	expression dependent on the context.
+        <emphasis>Build management.</emphasis>  In principle it is already
+        possible to do build management using Nix (by writing builders that
+        perform appropriate build steps), but the Nix expression language is
+        not yet powerful enough to make this pleasant (?).  The language should
+        be extended with features from the <ulink
+          url='http://www.cs.uu.nl/~eelco/maak/'>Maak build manager</ulink>.
+        Another interesting idea is to write a <command>make</command>
+        implementation that uses Nix as a back-end to support <ulink
+          url='http://www.research.att.com/~bs/bs_faq.html#legacy'>legacy</ulink> 
+        build files.
       </para>
     </listitem>
 
diff --git a/doc/manual/installation.xml b/doc/manual/installation.xml
index f9bd0a742fdf..3872a7fb8bf5 100644
--- a/doc/manual/installation.xml
+++ b/doc/manual/installation.xml
@@ -2,73 +2,113 @@
   <title>Installation</title>
 
   <sect1>
-    <title>Prerequisites</title>
+    <title>Obtaining Nix</title>
 
     <para>
-      Nix uses Sleepycat's Berkeley DB and CWI's ATerm library.  However, these
-      are fetched automatically as part of the build process.
+      The easiest way to obtain Nix is to download a <ulink
+        url='http://www.cs.uu.nl/groups/ST/Trace/Nix'>source
+        distribution.</ulink>  
     </para>
 
     <para>
-      Other than that, you need a good C++ compiler.  GCC 2.95 does not appear
-      to work; please use GCC 3.x.
-    </para>
-  </sect1>
-
-  <sect1>
-    <title>Obtaining Nix</title>
-
-    <para>
-      Nix can be obtained from its <ulink
-        url='http://losser.st-lab.cs.uu.nl:12080/repos/trace/nix/trunk'>Subversion 
+      Alternatively, the most recent sources of Nix can be obtained from its
+      <ulink url='https://svn.cs.uu.nl:12443/repos/trace/nix/trunk'>Subversion 
         repository</ulink>.  For example, the following command will check out
       the latest revision into a directory called <filename>nix</filename>:
     </para>
 
     <screen>
-$ svn checkout http://losser.st-lab.cs.uu.nl:12080/repos/trace/nix/trunk nix</screen>
+$ svn checkout https://svn.cs.uu.nl:12443/repos/trace/nix/trunk nix</screen>
 
     <para>
       Likewise, specific releases can be obtained from the <ulink
-        url='http://losser.st-lab.cs.uu.nl:12080/repos/trace/nix/tags'>tags
+        url='https://svn.cs.uu.nl:12443/repos/trace/nix/tags'>tags
         directory</ulink> of the repository.  If you don't have Subversion, you
-      can download a <ulink
-        url='http://losser.st-lab.cs.uu.nl:12080/dist/trace/'>compressed
-        tar-file</ulink> of the latest revision of the repository.
+      can also download an automatically generated <ulink
+        url='https://svn.cs.uu.nl:12443/dist/trace/'>compressed
+        tar-file</ulink> of the head revision of the trunk.
+    </para>
+
+  </sect1>
+
+  <sect1>
+    <title>Prerequisites</title>
+
+    <para>
+      A fairly recent version of GCC/G++ is required.  Version 2.95 and higher
+      should work.
+    </para>
+
+    <para>
+      To rebuild this manual and the man-pages you need the
+      <command>xmllint</command> and <command>xsltproc</command>, which are
+      part of the <literal>libxml2</literal> and <literal>libxslt</literal>
+      packages, respectively.  You also need the <ulink
+        url='http://docbook.sourceforge.net/projects/xsl/'>DocBook XSL
+        stylesheets</ulink> and optionally the <ulink
+        url='http://www.oasis-open.org/docbook/xml/4.2/docbook-xml-4.2.zip'>
+        DocBook XML 4.2 DTD</ulink>.  Note that these are only required if you
+      modify the manual sources or when you are building from the Subversion
+      repository.
     </para>
 
+    <para>
+      Nix uses Sleepycat's Berkeley DB, CWI's ATerm library, and SDF parser
+      library.  These are included in the Nix source distribution.  If you
+      build from the Subversion repository, you must download them yourself and
+      place them in the <filename>externals/</filename> directory.  See
+      <filename>externals/Makefile.am</filename> for the precise URLs of these
+      packages.
+    </para>
   </sect1>
 
   <sect1>
     <title>Building Nix</title>
 
     <para>
-      To build Nix, do the following:
+      After unpacking or checking out the Nix sources, issue the following
+      commands:
     </para>
 
     <screen>
-$ autoreconf -i
 $ ./configure <replaceable>options...</replaceable>
 $ make
 $ make install</screen>
 
     <para>
-      Currently, the only useful switch for <command>configure</command> is
-      <option>--prefix=<replaceable>prefix</replaceable></option> to specify
-      where Nix is to be installed.  The default installation directory is
+      When building from the Subversion repository, these should be preceded by
+      the command:
+    </para>
+
+    <screen>
+$ autoreconf -i</screen>
+
+    <para>
+      The installation path can be specified by passing the
+      <option>--prefix=<replaceable>prefix</replaceable></option> to
+      <command>configure</command>.  The default installation directory is
       <filename>/nix</filename>.  You can change this to any location you like.
-      You should ensure that you have write permission to the installation
-      prefix. 
+      You must have write permission to the <replaceable>prefix</replaceable>
+      path.
     </para>
 
     <warning>
       <para>
         It is advisable <emphasis>not</emphasis> to change the installation
-        prefix, since doing so will in all likelihood make it impossible to use
-        derivates built on other systems.
+        prefix from its default, since doing so will in all likelihood make it
+        impossible to use derivations built on other systems.
       </para>
     </warning>
 
+    <para>
+      If you want to rebuilt the documentation, pass the full path to the
+      DocBook XML catalog file (<filename>docbook.cat</filename>) and to the
+      DocBook XSL stylesheets using the
+      <option>--with-docbook-catalog=<replaceable>path</replaceable></option>
+      and <option>--with-docbook-xsl=<replaceable>path</replaceable></option>
+      options.
+    </para>
+
   </sect1>
 
 </chapter>
diff --git a/doc/manual/introduction.xml b/doc/manual/introduction.xml
index feabeef9cdc2..48e29c0d8f93 100644
--- a/doc/manual/introduction.xml
+++ b/doc/manual/introduction.xml
@@ -1,288 +1,93 @@
 <chapter>
   <title>Introduction</title>
 
-  <sect1>
-    <title>The problem space</title>
+  <para>
+    Nix is a system for software deployment.  It supports the
+    creation and distribution of software packages, as well as the installation
+    and subsequent management of these on target machines (i.e., it is also a
+    package manager).
+  </para>
+
+  <para>
+    Nix solves some large problems that exist in most current deployment and
+    package management systems.  <emphasis>Dependency determination</emphasis>
+    is a big one: the correct installation of a software component requires
+    that all dependencies of that component (i.e., other components used by it)
+    are also installed.  Most systems have no way to verify that the specified
+    dependencies of a component are actually sufficient.
+  </para>
+
+  <para>
+    Another big problem is the lack of support for concurrent availability of
+    multiple <emphasis>variants</emphasis> of a component.  It must be possible
+    to have several versions of a component installed at the same time, or
+    several instances of the same version built with different parameters.
+    Unfortunately, components are in general not properly isolated from each
+    other.  For instance, upgrading a component that is a dependency for some
+    other component might break the latter.
+  </para>
+
+  <para>
+    Nix solves these problems by building and storing packages in paths that
+    are infeasible to predict in advance.  For example, the artifacts of a
+    package <literal>X</literal> might be stored in
+    <filename>/nix/store/d58a0606ed616820de291d594602665d-X</filename>, rather
+    than in, say, <filename>/usr/lib</filename>.  The path component
+    <filename>d58a...</filename> is actually a cryptographic hash of all the
+    inputs (i.e., sources, requisites, and build flags) used in building
+    <literal>X</literal>, and as such is very fragile: any change to the inputs
+    will change the hash.  Therefore it is not sensible to
+    <emphasis>hard-code</emphasis> such a path into the build scripts of a
+    package <literal>Y</literal> that uses <literal>X</literal> (as does happen
+    with <quote>fixed</quote> paths such as <filename>/usr/lib</filename>).
+    Rather, the build script of package <literal>Y</literal> is parameterised
+    with the actual location of <literal>X</literal>, which is supplied by the
+    Nix system.
+  </para>
+
+  <para>
+    As stated above, the path name of a file system object contain a
+    cryptographic hash of all inputs involved in building it.  A change to any
+    of the inputs will cause the hash to change--and by extension, the path
+    name.  These inputs include both sources (variation in time) and
+    configuration options (variation in space).  Therefore variants of the same
+    package don't clash---they can co-exist peacefully within the same file
+    system.
+  </para>
+
+  <para>
+    Other features:
+  </para>
+
+  <para>
+    <emphasis>Transparent source/binary deployment.</emphasis>
+  </para>
+
+  <para>
+    <emphasis>Unambiguous identification of configuration.</emphasis>
+  </para>
+
+  <para>
+    <emphasis>Automatic storage management.</emphasis>
+  </para>
+
+  <para>
+    <emphasis>Atomic upgrades and rollbacks.</emphasis>
+  </para>
+
+  <para>
+    <emphasis>Support for many simultaneous configurations.</emphasis>
+  </para>
+
+  <para>
+    <emphasis>Portability.</emphasis>  Nix is quite portable.  Contrary to
+    build systems like those in, e.g., Vesta and ClearCase, it does not rely on
+    operating system extensions.
+  </para>
 
-    <para>
-      Nix is a system for controlling the automatic creation and distribution
-      of data, such as computer programs and other software artifacts.  This is
-      a very general problem, and there are many applications that fall under
-      this description.
-    </para>
-
-    <sect2>
-      <title>Build management</title>
-
-      <para>
-        Build management tools are used to perform <emphasis>software
-          builds</emphasis>, that is, the construction of derived products
-        (<emphasis>derivates)</emphasis>) such as executable programs from
-        source code.  A commonly used build tool is Make, which is a standard
-        tool on Unix systems. These tools have to deal with several issues:
-        <itemizedlist>
-
-          <listitem>
-            <para>
-              <emphasis>Efficiency</emphasis>.  Since building large systems
-              can take a substantial amount of time, it is desirable that build
-              steps that have been performed in the past are not repeated
-              unnecessarily, i.e., if a new build differs from a previous build
-              only with respect to certain sources, then only the build steps
-              that (directly or indirectly) <emphasis>depend</emphasis> on
-              those sources should be redone.
-            </para>
-          </listitem>
-
-          <listitem>
-            <para>
-              <emphasis>Correctness</emphasis> is this context means that the
-              derivates produced by a build are always consistent with the
-              sources, that is, they are equal to what we would get if we were
-              to build the derivates from those sources.  This requirement is
-              trivially met when we do a full, unconditional build, but is far
-              from trivial under the requirement of efficiency, since it is not
-              easy to determine which derivates are affected by a change to a
-              source.
-            </para>
-          </listitem>
-
-          <listitem>
-            <para>
-              <emphasis>Variability</emphasis> is the property that a software
-              system can be built in a (potentially large) number of variants.
-              Variation exists both in <emphasis>time</emphasis>---the
-              evolution of different versions of an artifact---and in
-              <emphasis>space</emphasis>---the artifact might have
-              configuration options that lead to variants that differ in the
-              features they support (for example, a system might be built with
-              or without debugging information).
-            </para>
-
-            <para>
-              Build managers historically have had good support for variation
-              in time (rebuilding the system in an intelligent way when sources
-              change is one of the primary reasons to use a build manager), but
-              not always for variation in space.  For example,
-              <command>make</command> will not automatically ensure that
-              variant builds are properly isolated from each other (they will
-              in fact overwrite each other unless special precautions are
-              taken).
-            </para>
-          </listitem>
-
-          <listitem>
-            <para>
-              <emphasis>High-level system modelling language</emphasis>.  The
-              language in which one describes what and how derivates are to be
-              produced should have sufficient abstraction facilities to make it
-              easy to specify the derivation of even very large systems.  Also,
-              the language should be <emphasis>modular</emphasis> to enable
-              components from possible different sources to be easily combined.
-            </para>
-          </listitem>
-
-        </itemizedlist>
-      </para>
-
-    </sect2>
-
-    <sect2>
-      <title>Package management</title>
-
-      <para>
-        After software has been built, is must also be
-        <emphasis>deployed</emphasis> in the intended target environment, e.g.,
-        the user's workstation.  Examples include the Red Hat package manager
-        (RPM), Microsoft's MSI, and so on.  Here also we have several issues to
-        contend with:
-        <itemizedlist>
-          <listitem>
-            <para>
-              The <emphasis>creation</emphasis> of packages from some formal
-              description of what artifacts should be distributed in the
-              package.
-            </para>
-          </listitem>
-          <listitem>
-            <para>
-              The <emphasis>deployment</emphasis> of packages, that is, the
-              mechanism by which we get them onto the intended target
-              environment.  This can be as simple as copying a file, but
-              complexity comes from the wide range of possible installation
-              media (such as a network install), and the scalability of the
-              process (if a program must be installed on a thousand systems, we
-              do not want to visit each system and perform some manual steps to
-              install the program on that system; that is, the complexity for
-              the system administrator should be constant, not linear).
-            </para>
-          </listitem>
-        </itemizedlist>
-      </para>
-    </sect2>
-
-  </sect1>
-
-
-  <!--######################################################################-->
-
-  <sect1>
-    <title>What Nix provides</title>
-
-    <para>
-      Here is a summary of Nix's main features:
-    </para>
-
-    <itemizedlist>
-
-      <listitem>
-        <para>
-          <emphasis>Reliable dependencies.</emphasis>  Builds of file system
-          objects depend on other file system object, such as source files,
-          tools, and so on.  We would like to ensure that a build does not
-          refer to any objects that have not been declared as inputs for that
-          build.  This is important for several reasons.  First, if any of the
-          inputs change, we need to rebuild the things that depend on them to
-          maintain consistency between sources and derivates.  Second, when we
-          <emphasis>deploy</emphasis> file system objects (that is, copy them
-          to a different system), we want to be certain that we copy everything
-          that we need.
-        </para>
-
-        <para>
-          Nix ensures this by building and storing file system objects in paths
-          that are infeasible to predict in advance.  For example, the
-          artifacts of a package <literal>X</literal> might be stored in
-          <filename>/nix/store/d58a0606ed616820de291d594602665d-X</filename>,
-          rather than in, say, <filename>/usr/lib</filename>.  The path
-          component <filename>d58a...</filename> is actually a cryptographic
-          hash of all the inputs (i.e., sources, requisites, and build flags)
-          used in building <literal>X</literal>, and as such is very fragile:
-          any change to the inputs will change the hash.  Therefore it is not
-          sensible to <emphasis>hard-code</emphasis> such a path into the build
-          scripts of a package <literal>Y</literal> that uses
-          <literal>X</literal> (as does happen with <quote>fixed</quote> paths
-          such as <filename>/usr/lib</filename>).  Rather, the build script of
-          package <literal>Y</literal> is parameterised with the actual
-          location of <literal>X</literal>, which is supplied by the Nix
-          system.
-        </para>
-      </listitem>
-
-      <listitem>
-        <para>
-          <emphasis>Support for variability.</emphasis>  
-        </para>
-        
-        <para>
-          As stated above, the path name of a file system object contain a
-          cryptographic hash of all inputs involved in building it.  A change to
-          any of the inputs will cause the hash to change--and by extension,
-          the path name.  These inputs include both sources (variation in time)
-          and configuration options (variation in space).  Therefore variants
-          of the same package don't clash---they can co-exist peacefully within
-          the same file system.  So thanks to Nix's mechanism for reliably
-          dealing with dependencies, we obtain management of variants for free
-          (or, to quote Simon Peyton-Jone, it's not free, but it has already
-          been paid for).
-        </para>
-
-      </listitem>
-
-      <listitem>
-        <para>
-          <emphasis>Transparent source/binary deployment.</emphasis>
-        </para>
-      </listitem>
-
-      <listitem>
-        <para>
-          <emphasis>Easy configuration duplication.</emphasis>
-        </para>
-      </listitem>
-
-      <listitem>
-        <para>
-          <emphasis>Automatic storage management.</emphasis>
-        </para>
-      </listitem>
-
-      <listitem>
-        <para>
-          <emphasis>Atomic upgrades and rollbacks.</emphasis>
-        </para>
-      </listitem>
-
-      <listitem>
-        <para>
-          <emphasis>Support for many simultaneous configurations.</emphasis>
-        </para>
-      </listitem>
-
-      <listitem>
-        <para>
-          <emphasis>Portability.</emphasis>  Nix is quite portable.  Contrary
-          to build systems like those in, e.g., Vesta and ClearCase [sic?], it
-          does not rely on operating system extensions.
-        </para>
-      </listitem>
-
-    </itemizedlist>
-
-    <para>
-      Here is what Nix doesn't yet provide, but will:
-    </para>
-
-    <itemizedlist>
-
-      <listitem>
-        <para>
-          <emphasis>Build management.</emphasis>  In principle it is already
-          possible to do build management using Fix (by writing builders that
-          perform appropriate build steps), but the Fix language is not yet
-          powerful enough to make this pleasant.  The <ulink
-            url='http://www.cs.uu.nl/~eelco/maak/'>Maak build manager</ulink>
-          should be retargeted to produce Nix expressions, or alternatively,
-          extend Fix with Maak's semantics and concrete syntax (since Fix needs
-          a concrete syntax anyway).  Another interesting idea is to write a
-          <command>make</command> implementation that uses Nix as a back-end to
-          support <ulink
-            url='http://www.research.att.com/~bs/bs_faq.html#legacy'>legacy</ulink> 
-          build files.
-        </para>
-      </listitem>
-
-    </itemizedlist>
-
-  </sect1>
-
-
-  <!--######################################################################-->
-
-  <sect1>
-    <title>The Nix system</title>
-
-    <para>
-      ...
-    </para>
-
-    <para>
-      Existing tools in this field generally both a underlying model (such as
-      the derivation graph of build tools, or the versioning scheme that
-      determines when two packages are <quote>compatible</quote> in a package
-      management system) and a formalism that allows ...
-    </para>
-
-    <para>
-      Following the principle of separation of mechanism and policy, the Nix
-      system separates the <emphasis>low-level aspect</emphasis> of file system
-      object management form the <emphasis>high-level aspect</emphasis> of the
-      ...
-    </para>
+</chapter>
 
-  </sect1>
 
-</chapter>
 
 <!--
 local variables:
diff --git a/doc/manual/troubleshooting.xml b/doc/manual/troubleshooting.xml
index 6c40775dbe69..1e35c6079538 100644
--- a/doc/manual/troubleshooting.xml
+++ b/doc/manual/troubleshooting.xml
@@ -2,27 +2,6 @@
   <title>Troubleshooting</title>
 
   <sect1>
-    <title>Database hangs</title>
-
-    <para>
-      If Nix or Fix appear to hang immediately after they are started, Nix's
-      database is probably <quote>wedged</quote>, i.e., some process died while
-      it held a lock on the database.  The solution is to ensure that no other
-      processes are accessing the database and then run the following command:
-    </para>
-
-    <screen>
-      $ db_recover -e -h <replaceable>prefix</replaceable>/var/nix/db</screen>
-
-    <para>
-      Here, <replaceable>prefix</replaceable> should be replaced by Nix's
-      installation prefix.
-    </para>
-
-  </sect1>
-
-
-  <sect1>
     <title>Database logfile removal</title>
 
     <para>