error: root struct of file 'Build.Step' has no member named 'MakeOptions'

[whileunless]

I am trying to build it, after git clone https://github.com/zig-bitcoin/coconut.git,
zig build -Doptimize=ReleaseFast gives me:

/home/j/.cache/zig/p/122005e589ab3b6bff8e589b45f5b12cd27ce79f266bdac17e9f33ebfe2fbaff7fe3/build.zig:66:61: error: root struct of file 'Build.Step' has no member named 'MakeOptions'
            fn make(step: *std.Build.Step, _: std.Build.Step.MakeOptions) anyerror!void {
                                              ~~~~~~~~~~~~~~^~~~~~~~~~~~
/opt/zig-linux-x86_64-0.13.0/lib/std/Build/Step.zig:1:1: note: struct declared here
id: Id,
^~
referenced by:
    readMeStep: /home/j/.cache/zig/p/122005e589ab3b6bff8e589b45f5b12cd27ce79f266bdac17e9f33ebfe2fbaff7fe3/build.zig:79:10
    build: /home/j/.cache/zig/p/122005e589ab3b6bff8e589b45f5b12cd27ce79f266bdac17e9f33ebfe2fbaff7fe3/build.zig:47:20
    remaining reference traces hidden; use '-freference-trace' to see all reference traces

zig build -Doptimize=ReleaseFast -freference-trace gives me:

referenced by:
    readMeStep: /home/j/.cache/zig/p/122005e589ab3b6bff8e589b45f5b12cd27ce79f266bdac17e9f33ebfe2fbaff7fe3/build.zig:79:10
    build: /home/j/.cache/zig/p/122005e589ab3b6bff8e589b45f5b12cd27ce79f266bdac17e9f33ebfe2fbaff7fe3/build.zig:47:20
    runBuild__anon_15641: /opt/zig-linux-x86_64-0.13.0/lib/std/Build.zig:2116:27
    dependencyInner__anon_14672: /opt/zig-linux-x86_64-0.13.0/lib/std/Build.zig:2097:29
    dependency__anon_11209: /opt/zig-linux-x86_64-0.13.0/lib/std/Build.zig:1954:35
    generateModuleDependencies__anon_11154: /usr/local/src/coconut/build_helpers.zig:26:36
    build: /usr/local/src/coconut/build.zig:51:58
    runBuild__anon_8822: /opt/zig-linux-x86_64-0.13.0/lib/std/Build.zig:2117:37
    main: /opt/zig-linux-x86_64-0.13.0/lib/compiler/build_runner.zig:301:29
    callMain: /opt/zig-linux-x86_64-0.13.0/lib/std/start.zig:524:32
    callMainWithArgs: /opt/zig-linux-x86_64-0.13.0/lib/std/start.zig:482:12
    posixCallMainAndExit: /opt/zig-linux-x86_64-0.13.0/lib/std/start.zig:438:20
    _start: /opt/zig-linux-x86_64-0.13.0/lib/std/start.zig:351:40

I'm on Ubuntu 22.04LTS, I use zig 0.13.0 installed via direct-download.