doc: Improve code listings

By adding prompts and removing unnecessary indentation.

(cherry picked from commit e1af37634b)

doc/builders/images/dockertools.xml

@@ -132,11 +132,11 @@ buildImage {
    <para>
     By default <function>buildImage</function> will use a static date of one second past the UNIX Epoch. This allows <function>buildImage</function> to produce binary reproducible images. When listing images with <command>docker images</command>, the newly created images will be listed like this:
    </para>
-<screen><![CDATA[
-$ docker images
+<screen>
+<prompt>$ </prompt>docker images
 REPOSITORY   TAG      IMAGE ID       CREATED        SIZE
 hello        latest   08c791c7846e   48 years ago   25.2MB
-]]></screen>
+</screen>
    <para>
     You can break binary reproducibility but have a sorted, meaningful <literal>CREATED</literal> column by setting <literal>created</literal> to <literal>now</literal>.
    </para>
@@ -152,11 +152,11 @@ pkgs.dockerTools.buildImage {
 ]]></programlisting>
    <para>
     and now the Docker CLI will display a reasonable date and sort the images as expected:
-<screen><![CDATA[
-$ docker images
+<screen>
+<prompt>$ </prompt>docker images
 REPOSITORY   TAG      IMAGE ID       CREATED              SIZE
 hello        latest   de2bf4786de6   About a minute ago   25.2MB
-]]></screen>
+</screen>
     however, the produced images will not be binary reproducible.
    </para>
   </example>

doc/builders/images/ocitools.xml

@@ -38,8 +38,7 @@ buildContainer {
 
   readonly = false; <co xml:id='ex-ociTools-buildContainer-3' />
 }
-
-    </programlisting>
+</programlisting>
    <calloutlist>
     <callout arearefs='ex-ociTools-buildContainer-1'>
      <para>

doc/builders/packages/citrix.xml

@@ -22,10 +22,10 @@
   </para>
   <para>
    In order to set this up, you first have to <link xlink:href="https://its.uiowa.edu/support/article/102186">download the <literal>.cr</literal> file from the Netscaler Gateway</link>. After that you can configure the <command>selfservice</command> like this:
-   <screen>
-    <prompt>$ </prompt>storebrowse -C ~/Downloads/receiverconfig.cr
-    <prompt>$ </prompt>selfservice
-   </screen>
+<screen>
+<prompt>$ </prompt>storebrowse -C ~/Downloads/receiverconfig.cr
+<prompt>$ </prompt>selfservice
+</screen>
   </para>
  </section>
 

doc/builders/packages/urxvt.xml

@@ -18,10 +18,13 @@
    includes all available plugins. To make use of this functionality, use an
    overlay or directly install an expression that overrides its configuration,
    such as
-   <programlisting>rxvt-unicode.override { configure = { availablePlugins, ... }: {
+<programlisting>
+rxvt-unicode.override {
+  configure = { availablePlugins, ... }: {
     plugins = with availablePlugins; [ perls resize-font vtwheel ];
-  }
-}</programlisting>
+  };
+}
+</programlisting>
    If the <literal>configure</literal> function returns an attrset without the
    <literal>plugins</literal> attribute, <literal>availablePlugins</literal>
    will be used automatically.
@@ -30,18 +33,22 @@
   <para>
    In order to add plugins but also keep all default plugins installed, it is
    possible to use the following method:
-   <programlisting>rxvt-unicode.override { configure = { availablePlugins, ... }: {
-     plugins = (builtins.attrValues availablePlugins) ++ [ custom-plugin ];
-   };
-}</programlisting>
+<programlisting>
+rxvt-unicode.override {
+  configure = { availablePlugins, ... }: {
+    plugins = (builtins.attrValues availablePlugins) ++ [ custom-plugin ];
+  };
+}
+</programlisting>
   </para>
 
   <para>
    To get a list of all the plugins available, open the Nix REPL and run
-   <programlisting>$ nix repl
+<screen>
+<prompt>$ </prompt>nix repl
 :l &lt;nixpkgs&gt;
 map (p: p.name) pkgs.rxvt-unicode.plugins
-   </programlisting>
+</screen>
    Alternatively, if your shell is bash or zsh and have completion enabled,
    simply type <literal>nixpkgs.rxvt-unicode.plugins.&lt;tab&gt;</literal>.
   </para>
@@ -53,18 +60,24 @@ map (p: p.name) pkgs.rxvt-unicode.plugins
     <literal>extraDeps</literal> can be used, for example, to provide
     <literal>xsel</literal> (a clipboard manager) to the clipboard plugin,
     without installing it globally:
-    <programlisting>rxvt-unicode.override { configure = { availablePlugins, ... }: {
-     pluginsDeps = [ xsel ];
-   }
-}</programlisting>
+<programlisting>
+rxvt-unicode.override {
+  configure = { availablePlugins, ... }: {
+    pluginsDeps = [ xsel ];
+  };
+}
+</programlisting>
 
     <literal>perlDeps</literal> is a handy way to provide Perl packages to
     your custom plugins (in <literal>$HOME/.urxvt/ext</literal>). For example,
     if you need <literal>AnyEvent</literal> you can do:
-    <programlisting>rxvt-unicode.override { configure = { availablePlugins, ... }: {
-     perlDeps = with perlPackages; [ AnyEvent ];
-   }
-}</programlisting>
+<programlisting>
+rxvt-unicode.override {
+  configure = { availablePlugins, ... }: {
+    perlDeps = with perlPackages; [ AnyEvent ];
+  };
+}
+</programlisting>
   </para>
 
  </section>
@@ -90,7 +103,8 @@ map (p: p.name) pkgs.rxvt-unicode.plugins
   <para>
    If the plugin is itself a perl package that needs to be imported from
    other plugins or scripts, add the following passthrough:
-   <programlisting>passthru.perlPackages = [ "self" ];
+<programlisting>
+passthru.perlPackages = [ "self" ];
 </programlisting>
    This will make the urxvt wrapper pick up the dependency and set up the perl
    path accordingly.

doc/contributing/submitting-changes.xml

@@ -209,12 +209,12 @@ Additional information.
   </para>
 
 <programlisting>
-   (fetchpatch {
-     name = "CVE-2019-11068.patch";
-     url = "https://gitlab.gnome.org/GNOME/libxslt/commit/e03553605b45c88f0b4b2980adfbbb8f6fca2fd6.patch";
-     sha256 = "0pkpb4837km15zgg6h57bncp66d5lwrlvkr73h0lanywq7zrwhj8";
-   })
-  </programlisting>
+(fetchpatch {
+  name = "CVE-2019-11068.patch";
+  url = "https://gitlab.gnome.org/GNOME/libxslt/commit/e03553605b45c88f0b4b2980adfbbb8f6fca2fd6.patch";
+  sha256 = "0pkpb4837km15zgg6h57bncp66d5lwrlvkr73h0lanywq7zrwhj8";
+})
+</programlisting>
 
   <para>
    If a security fix applies to both master and a stable release then, similar to regular changes, they are preferably delivered via master first and cherry-picked to the release branch.

doc/languages-frameworks/beam.xml

@@ -72,9 +72,9 @@
    To install any of those builders into your profile, refer to them by their attribute path <literal>beamPackages.rebar3</literal>:
   </para>
 
-  <screen>
-  <prompt>$ </prompt>nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.rebar3
-  </screen>
+<screen>
+<prompt>$ </prompt>nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.rebar3
+</screen>
 </section>
 
  <section xml:id="packaging-beam-applications">

doc/languages-frameworks/perl.xml

@@ -8,28 +8,28 @@
 
   <para>
    When executing a Perl script, it is possible you get an error such as <literal>./myscript.pl: bad interpreter: /usr/bin/perl: no such file or directory</literal>. This happens when the script expects Perl to be installed at <filename>/usr/bin/perl</filename>, which is not the case when using Perl from nixpkgs. You can fix the script by changing the first line to:
-  <programlisting>
-  #!/usr/bin/env perl
-  </programlisting>
+<programlisting>
+#!/usr/bin/env perl
+</programlisting>
   to take the Perl installation from the <literal>PATH</literal> environment variable, or invoke Perl directly with:
-  <screen>
-  <prompt>$ </prompt>perl ./myscript.pl
-  </screen>
+<screen>
+<prompt>$ </prompt>perl ./myscript.pl
+</screen>
   </para>
 
   <para>
    When the script is using a Perl library that is not installed globally, you might get an error such as <literal>Can't locate DB_File.pm in @INC (you may need to install the DB_File module)</literal>. In that case, you can use <command>nix-shell</command> to start an ad-hoc shell with that library installed, for instance:
-  <screen>
-  <prompt>$ </prompt>nix-shell -p perl perlPackages.DBFile --run ./myscript.pl
-  </screen>
+<screen>
+<prompt>$ </prompt>nix-shell -p perl perlPackages.DBFile --run ./myscript.pl
+</screen>
   </para>
 
   <para>
   If you are always using the script in places where <command>nix-shell</command> is available, you can embed the <command>nix-shell</command> invocation in the shebang like this:
-  <programlisting>
-  #!/usr/bin/env nix-shell
-  #! nix-shell -i perl -p perl perlPackages.DBFile
-  </programlisting>
+<programlisting>
+#!/usr/bin/env nix-shell
+#! nix-shell -i perl -p perl perlPackages.DBFile
+</programlisting>
   </para>
  </section>
 
@@ -44,30 +44,30 @@
   <para>
    Perl packages from CPAN are defined in <link
  xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix"><filename>pkgs/top-level/perl-packages.nix</filename></link>, rather than <filename>pkgs/all-packages.nix</filename>. Most Perl packages are so straight-forward to build that they are defined here directly, rather than having a separate function for each package called from <filename>perl-packages.nix</filename>. However, more complicated packages should be put in a separate file, typically in <filename>pkgs/development/perl-modules</filename>. Here is an example of the former:
- <programlisting>
- ClassC3 = buildPerlPackage rec {
-   name = "Class-C3-0.21";
-   src = fetchurl {
-     url = "mirror://cpan/authors/id/F/FL/FLORA/${name}.tar.gz";
-     sha256 = "1bl8z095y4js66pwxnm7s853pi9czala4sqc743fdlnk27kq94gz";
-   };
- };
- </programlisting>
+<programlisting>
+ClassC3 = buildPerlPackage rec {
+  name = "Class-C3-0.21";
+  src = fetchurl {
+    url = "mirror://cpan/authors/id/F/FL/FLORA/${name}.tar.gz";
+    sha256 = "1bl8z095y4js66pwxnm7s853pi9czala4sqc743fdlnk27kq94gz";
+  };
+};
+</programlisting>
    Note the use of <literal>mirror://cpan/</literal>, and the <literal>${name}</literal> in the URL definition to ensure that the name attribute is consistent with the source that we’re actually downloading. Perl packages are made available in <filename>all-packages.nix</filename> through the variable <varname>perlPackages</varname>. For instance, if you have a package that needs <varname>ClassC3</varname>, you would typically write
- <programlisting>
- foo = import ../path/to/foo.nix {
-   inherit stdenv fetchurl ...;
-   inherit (perlPackages) ClassC3;
- };
- </programlisting>
+<programlisting>
+foo = import ../path/to/foo.nix {
+  inherit stdenv fetchurl ...;
+  inherit (perlPackages) ClassC3;
+};
+</programlisting>
    in <filename>all-packages.nix</filename>. You can test building a Perl package as follows:
- <screen>
- <prompt>$ </prompt>nix-build -A perlPackages.ClassC3
- </screen>
+<screen>
+<prompt>$ </prompt>nix-build -A perlPackages.ClassC3
+</screen>
    <varname>buildPerlPackage</varname> adds <literal>perl-</literal> to the start of the name attribute, so the package above is actually called <literal>perl-Class-C3-0.21</literal>. So to install it, you can say:
- <screen>
- <prompt>$ </prompt>nix-env -i perl-Class-C3
- </screen>
+<screen>
+<prompt>$ </prompt>nix-env -i perl-Class-C3
+</screen>
    (Of course you can also install using the attribute name: <literal>nix-env -i -A perlPackages.ClassC3</literal>.)
   </para>
 
@@ -94,61 +94,61 @@
 
   <para>
    <varname>buildPerlPackage</varname> is built on top of <varname>stdenv</varname>, so everything can be customised in the usual way. For instance, the <literal>BerkeleyDB</literal> module has a <varname>preConfigure</varname> hook to generate a configuration file used by <filename>Makefile.PL</filename>:
- <programlisting>
- { buildPerlPackage, fetchurl, db }:
-
- buildPerlPackage rec {
-   name = "BerkeleyDB-0.36";
-
-   src = fetchurl {
-     url = "mirror://cpan/authors/id/P/PM/PMQS/${name}.tar.gz";
-     sha256 = "07xf50riarb60l1h6m2dqmql8q5dij619712fsgw7ach04d8g3z1";
-   };
-
-   preConfigure = ''
-     echo "LIB = ${db.out}/lib" > config.in
-     echo "INCLUDE = ${db.dev}/include" >> config.in
-   '';
- }
- </programlisting>
+<programlisting>
+{ buildPerlPackage, fetchurl, db }:
+
+buildPerlPackage rec {
+  name = "BerkeleyDB-0.36";
+
+  src = fetchurl {
+    url = "mirror://cpan/authors/id/P/PM/PMQS/${name}.tar.gz";
+    sha256 = "07xf50riarb60l1h6m2dqmql8q5dij619712fsgw7ach04d8g3z1";
+  };
+
+  preConfigure = ''
+    echo "LIB = ${db.out}/lib" > config.in
+    echo "INCLUDE = ${db.dev}/include" >> config.in
+  '';
+}
+</programlisting>
   </para>
 
   <para>
    Dependencies on other Perl packages can be specified in the <varname>buildInputs</varname> and <varname>propagatedBuildInputs</varname> attributes. If something is exclusively a build-time dependency, use <varname>buildInputs</varname>; if it’s (also) a runtime dependency, use <varname>propagatedBuildInputs</varname>. For instance, this builds a Perl module that has runtime dependencies on a bunch of other modules:
- <programlisting>
- ClassC3Componentised = buildPerlPackage rec {
-   name = "Class-C3-Componentised-1.0004";
-   src = fetchurl {
-     url = "mirror://cpan/authors/id/A/AS/ASH/${name}.tar.gz";
-     sha256 = "0xql73jkcdbq4q9m0b0rnca6nrlvf5hyzy8is0crdk65bynvs8q1";
-   };
-   propagatedBuildInputs = [
-     ClassC3 ClassInspector TestException MROCompat
-   ];
- };
- </programlisting>
+<programlisting>
+ClassC3Componentised = buildPerlPackage rec {
+  name = "Class-C3-Componentised-1.0004";
+  src = fetchurl {
+    url = "mirror://cpan/authors/id/A/AS/ASH/${name}.tar.gz";
+    sha256 = "0xql73jkcdbq4q9m0b0rnca6nrlvf5hyzy8is0crdk65bynvs8q1";
+  };
+  propagatedBuildInputs = [
+    ClassC3 ClassInspector TestException MROCompat
+  ];
+};
+</programlisting>
   </para>
 
   <para>
    On Darwin, if a script has too many <literal>-I<replaceable>dir</replaceable></literal> flags in its first line (its “shebang line”), it will not run. This can be worked around by calling the <literal>shortenPerlShebang</literal> function from the <literal>postInstall</literal> phase:
- <programlisting>
- { stdenv, buildPerlPackage, fetchurl, shortenPerlShebang }:
-
- ImageExifTool = buildPerlPackage {
-   pname = "Image-ExifTool";
-   version = "11.50";
-
-   src = fetchurl {
-     url = "https://www.sno.phy.queensu.ca/~phil/exiftool/Image-ExifTool-11.50.tar.gz";
-     sha256 = "0d8v48y94z8maxkmw1rv7v9m0jg2dc8xbp581njb6yhr7abwqdv3";
-   };
-
-   buildInputs = stdenv.lib.optional stdenv.isDarwin shortenPerlShebang;
-   postInstall = stdenv.lib.optional stdenv.isDarwin ''
-     shortenPerlShebang $out/bin/exiftool
-   '';
- };
- </programlisting>
+<programlisting>
+{ stdenv, buildPerlPackage, fetchurl, shortenPerlShebang }:
+
+ImageExifTool = buildPerlPackage {
+  pname = "Image-ExifTool";
+  version = "11.50";
+
+  src = fetchurl {
+    url = "https://www.sno.phy.queensu.ca/~phil/exiftool/Image-ExifTool-11.50.tar.gz";
+    sha256 = "0d8v48y94z8maxkmw1rv7v9m0jg2dc8xbp581njb6yhr7abwqdv3";
+  };
+
+  buildInputs = stdenv.lib.optional stdenv.isDarwin shortenPerlShebang;
+  postInstall = stdenv.lib.optional stdenv.isDarwin ''
+    shortenPerlShebang $out/bin/exiftool
+  '';
+};
+</programlisting>
    This will remove the <literal>-I</literal> flags from the shebang line, rewrite them in the <literal>use lib</literal> form, and put them on the next line instead. This function can be given any number of Perl scripts as arguments; it will modify them in-place.
   </para>
 
@@ -159,27 +159,27 @@
     Nix expressions for Perl packages can be generated (almost) automatically from CPAN. This is done by the program <command>nix-generate-from-cpan</command>, which can be installed as follows:
    </para>
 
- <screen>
- <prompt>$ </prompt>nix-env -i nix-generate-from-cpan
- </screen>
+<screen>
+<prompt>$ </prompt>nix-env -i nix-generate-from-cpan
+</screen>
 
    <para>
     This program takes a Perl module name, looks it up on CPAN, fetches and unpacks the corresponding package, and prints a Nix expression on standard output. For example:
- <screen>
- <prompt>$ </prompt>nix-generate-from-cpan XML::Simple
-   XMLSimple = buildPerlPackage rec {
-     name = "XML-Simple-2.22";
-     src = fetchurl {
-       url = "mirror://cpan/authors/id/G/GR/GRANTM/${name}.tar.gz";
-       sha256 = "b9450ef22ea9644ae5d6ada086dc4300fa105be050a2030ebd4efd28c198eb49";
-     };
-     propagatedBuildInputs = [ XMLNamespaceSupport XMLSAX XMLSAXExpat ];
-     meta = {
-       description = "An API for simple XML files";
-       license = with stdenv.lib.licenses; [ artistic1 gpl1Plus ];
-     };
-   };
- </screen>
+<screen>
+<prompt>$ </prompt>nix-generate-from-cpan XML::Simple
+  XMLSimple = buildPerlPackage rec {
+    name = "XML-Simple-2.22";
+    src = fetchurl {
+      url = "mirror://cpan/authors/id/G/GR/GRANTM/${name}.tar.gz";
+      sha256 = "b9450ef22ea9644ae5d6ada086dc4300fa105be050a2030ebd4efd28c198eb49";
+    };
+    propagatedBuildInputs = [ XMLNamespaceSupport XMLSAX XMLSAXExpat ];
+    meta = {
+      description = "An API for simple XML files";
+      license = with stdenv.lib.licenses; [ artistic1 gpl1Plus ];
+    };
+  };
+</screen>
     The output can be pasted into <filename>pkgs/top-level/perl-packages.nix</filename> or wherever else you need it.
    </para>
   </section>

doc/languages-frameworks/qt.xml

@@ -18,7 +18,7 @@ mkDerivation { <co xml:id='qt-default-nix-co-2' />
 
   buildInputs = [ qtbase ]; <co xml:id='qt-default-nix-co-3' />
 }
-   </programlisting>
+</programlisting>
  </example>
 
  <calloutlist>

doc/languages-frameworks/ruby.xml

@@ -12,14 +12,14 @@
  </para>
 
 <screen>
-<![CDATA[$ cd pkgs/servers/monitoring
-$ mkdir sensu
-$ cd sensu
-$ cat > Gemfile
+<prompt>$ </prompt>cd pkgs/servers/monitoring
+<prompt>$ </prompt>mkdir sensu
+<prompt>$ </prompt>cd sensu
+<prompt>$ </prompt>cat > Gemfile
 source 'https://rubygems.org'
 gem 'sensu'
-$ $(nix-build '<nixpkgs>' -A bundix --no-out-link)/bin/bundix --magic
-$ cat > default.nix
+<prompt>$ </prompt>$(nix-build '&lt;nixpkgs>' -A bundix --no-out-link)/bin/bundix --magic
+<prompt>$ </prompt>cat > default.nix
 { lib, bundlerEnv, ruby }:
 
 bundlerEnv rec {
@@ -37,7 +37,7 @@ bundlerEnv rec {
     maintainers = with maintainers; [ theuni ];
     platforms   = platforms.unix;
   };
-}]]>
+}
 </screen>
 
  <para>
@@ -49,17 +49,16 @@ bundlerEnv rec {
  </para>
 
 <screen>
-<![CDATA[$ cd pkgs/servers/monitoring/sensu
-$ nix-shell -p bundler --run 'bundle lock --update'
-$ nix-shell -p bundix --run 'bundix'
-]]>
+<prompt>$ </prompt>cd pkgs/servers/monitoring/sensu
+<prompt>$ </prompt>nix-shell -p bundler --run 'bundle lock --update'
+<prompt>$ </prompt>nix-shell -p bundix --run 'bundix'
 </screen>
 
  <para>
   For tools written in Ruby - i.e. where the desire is to install a package and then execute e.g. <command>rake</command> at the command line, there is an alternative builder called <literal>bundlerApp</literal>. Set up the <filename>gemset.nix</filename> the same way, and then, for example:
  </para>
 
-<screen>
+<programlisting>
 <![CDATA[{ lib, bundlerApp }:
 
 bundlerApp {
@@ -75,7 +74,7 @@ bundlerApp {
     platforms   = platforms.unix;
   };
 }]]>
-</screen>
+</programlisting>
 
  <para>
   The chief advantage of <literal>bundlerApp</literal> over <literal>bundlerEnv</literal> is the executables introduced in the environment are precisely those selected in the <literal>exes</literal> list, as opposed to <literal>bundlerEnv</literal> which adds all the executables made available by gems in the gemset, which can mean e.g. <command>rspec</command> or <command>rake</command> in unpredictable versions available from various packages.

doc/languages-frameworks/texlive.xml

@@ -44,11 +44,11 @@ texlive.combine {
    <listitem>
     <para>
      You can list packages e.g. by <command>nix repl</command>.
-<programlisting><![CDATA[
-$ nix repl
-nix-repl> :l <nixpkgs>
-nix-repl> texlive.collection-<TAB>
-]]></programlisting>
+<programlisting>
+<prompt>$ </prompt>nix repl
+<prompt>nix-repl> </prompt>:l &lt;nixpkgs>
+<prompt>nix-repl> </prompt>texlive.collection-<keycap function="tab" />
+</programlisting>
     </para>
    </listitem>
    <listitem>

doc/stdenv/multiple-output.xml

@@ -67,7 +67,7 @@
     <para>
      <command>nix-env</command> silenty disregards the outputs selected by the user, and instead installs the outputs from <varname>meta.outputsToInstall</varname>. For example,
     </para>
-<programlisting>$ nix-env -iA nixpkgs.coreutils.info</programlisting>
+<screen><prompt>$ </prompt>nix-env -iA nixpkgs.coreutils.info</screen>
     <para>
      installs the <literal>"out"</literal> output (<varname>coreutils.meta.outputsToInstall</varname> is <literal>[ "out" ]</literal>) instead of the requested <literal>"info"</literal>.
     </para>

doc/using/configuration.xml

@@ -66,7 +66,7 @@
    <listitem>
     <para>
      For allowing the build of a broken package once, you can use an environment variable for a single invocation of the nix tools:
-<programlisting>$ export NIXPKGS_ALLOW_BROKEN=1</programlisting>
+<screen><prompt>$ </prompt>export NIXPKGS_ALLOW_BROKEN=1</screen>
     </para>
    </listitem>
    <listitem>
@@ -92,7 +92,7 @@
    <listitem>
     <para>
      For allowing the build of an unsupported package once, you can use an environment variable for a single invocation of the nix tools:
-<programlisting>$ export NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1</programlisting>
+<screen><prompt>$ </prompt>export NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1</screen>
     </para>
    </listitem>
    <listitem>
@@ -122,7 +122,7 @@
    <listitem>
     <para>
      To temporarily allow all unfree packages, you can use an environment variable for a single invocation of the nix tools:
-<programlisting>$ export NIXPKGS_ALLOW_UNFREE=1</programlisting>
+<screen><prompt>$ </prompt>export NIXPKGS_ALLOW_UNFREE=1</screen>
     </para>
    </listitem>
    <listitem>
@@ -187,7 +187,7 @@
    <listitem>
     <para>
      To temporarily allow all insecure packages, you can use an environment variable for a single invocation of the nix tools:
-<programlisting>$ export NIXPKGS_ALLOW_INSECURE=1</programlisting>
+<screen><prompt>$ </prompt>export NIXPKGS_ALLOW_INSECURE=1</screen>
     </para>
    </listitem>
    <listitem>

doc/using/overlays.xml

@@ -226,7 +226,7 @@ self: super:
     lapackProvider = self.mkl;
   }
 }
-     </programlisting>
+</programlisting>
      <para>
        This overlay uses Intel’s MKL library for both BLAS and LAPACK
        interfaces. Note that the same can be accomplished at runtime
@@ -234,9 +234,9 @@ self: super:
        <literal>libblas.so.3</literal> and
        <literal>liblapack.so.3</literal>. For instance:
      </para>
-     <programlisting>
-$ LD_LIBRARY_PATH=$(nix-build -A mkl)/lib:$LD_LIBRARY_PATH nix-shell -p octave --run octave
-     </programlisting>
+<screen>
+<prompt>$ </prompt>LD_LIBRARY_PATH=$(nix-build -A mkl)/lib:$LD_LIBRARY_PATH nix-shell -p octave --run octave
+</screen>
      <para>
        Intel MKL requires an <literal>openmp</literal> implementation
        when running with multiple processors. By default,
@@ -274,7 +274,7 @@ assert (!blas.isILP64) &amp;&amp; (!lapack.isILP64);
 stdenv.mkDerivation {
   ...
 }
-     </programlisting>
+</programlisting>
    </section>
  </section>
 </chapter>