</varlistentry>
<varlistentry id="configure-with-tcl-version-meson">
<term><option>-Dtcl_version=<replaceable>TCL_VERSION</replaceable></option></term>
<listitem>
<para>
Specifies the Tcl version to use when building PL/Tcl.
</para>
</listitem>
</varlistentry>
<varlistentry id="configure-with-icu-meson">
<term><option>-Dicu={ auto | enabled | disabled }</option></term>
<listitem>
<para>
Build with support for the
<productname>ICU</productname><indexterm><primary>ICU</primary></indexterm>
library, enabling use of ICU collation features (see <xref
linkend="collation"/>). Defaults to auto and requires the
<productname>ICU4C</productname> package to be installed. The minimum
required version of <productname>ICU4C</productname> is currently 4.2.
</para>
</listitem>
</varlistentry>
<varlistentry id="configure-with-llvm-meson">
<term><option>-Dllvm={ auto | enabled | disabled }</option></term>
<listitem>
<para>
Build with support for <productname>LLVM</productname> based
<acronym>JIT</acronym> compilation (see <xref linkend="jit"/>).
This requires the <productname>LLVM</productname> library to be
installed. The minimum required version of
<productname>LLVM</productname> is currently 14. Disabled by
default.
</para>
<para>
<command>llvm-config</command><indexterm><primary>llvm-config</primary></indexterm>
will be used to find the required compilation options.
<command>llvm-config</command>, and then
<command>llvm-config-$version</command> for all supported versions,
will be searched for in your <envar>PATH</envar>. If that would not
yield the desired program, use <envar>LLVM_CONFIG</envar> to specify a
path to the correct <command>llvm-config</command>.
</para>
</listitem>
</varlistentry>
<varlistentry id="configure-with-lz4-meson">
<term><option>-Dlz4={ auto | enabled | disabled }</option></term>
<listitem>
<para>
Build with <productname>LZ4</productname> compression support.
Defaults to auto.
</para>
</listitem>
</varlistentry>
<varlistentry id="configure-with-zstd-meson">
<term><option>-Dzstd={ auto | enabled | disabled }</option></term>
<listitem>
<para>
Build with <productname>Zstandard</productname> compression support.
Defaults to auto.
</para>
</listitem>
</varlistentry>
<varlistentry id="configure-with-ssl-meson">
<term><option>-Dssl={ auto | <replaceable>LIBRARY</replaceable> }</option>
<indexterm>
<primary>OpenSSL</primary>
<seealso>SSL</seealso>
</indexterm>
</term>
<listitem>
<para>
Build with support for <acronym>SSL</acronym> (encrypted) connections.
The only <replaceable>LIBRARY</replaceable> supported is
<option>openssl</option>. This requires the
<productname>OpenSSL</productname> package to be installed. Building
with this will check for the required header files and libraries to
make sure that your <productname>OpenSSL</productname> installation is
sufficient before proceeding. The default for this option is auto.
</para>
</listitem>
</varlistentry>
<varlistentry id="configure-with-gssapi-meson">
<term><option>-Dgssapi={ auto | enabled | disabled }</option></term>
<listitem>
<para>
Build with support for GSSAPI authentication. MIT Kerberos is required
to be installed for GSSAPI. On many systems, the GSSAPI system (a part
of the MIT Kerberos installation) is not installed in a location
that is searched by default (e.g., <filename>/usr/include</filename>,
<filename>/usr/lib</filename>). In
those