Cannot compile ixion-0.18

[graywolf-s1]

Compilation of ixion-0.18 fails when trying to install it (as a dependency for libreoffice).

--->  Fetching archive for ixion-0.18
--->  Attempting to fetch ixion-0.18-0.18.1_1.darwin_23.arm64.tbz2 from https://vie.at.packages.macports.org/ixion-0.18
--->  Attempting to fetch ixion-0.18-0.18.1_1.darwin_23.arm64.tbz2 from https://packages.macports.org/ixion-0.18
--->  Attempting to fetch ixion-0.18-0.18.1_1.darwin_23.arm64.tbz2 from https://fra.de.packages.macports.org/ixion-0.18
--->  Fetching distfiles for ixion-0.18
--->  Verifying checksums for ixion-0.18
--->  Extracting ixion-0.18
--->  Configuring ixion-0.18
--->  Building ixion-0.18                                
Error: Failed to build ixion-0.18: command execution failed
Error: See /opt/local/var/macports/logs/_Users_tomas.volf_src_ports_devel_ixion-0.18/ixion-0.18/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets if you believe there is a bug.

First error from the log file:

:info:build In file included from document.cpp:8:
:info:build ../../include/ixion/document.hpp:47:14: error: no template named 'variant' in namespace 'std'
:info:build         std::variant<std::string_view, ixion::abs_address_t> value;
:info:build         ~~~~~^

[graywolf-s1]

Log file from the build