FrontierSWE v2 traces: agents copy stock Wan 2.1 code, then burn 10 hours on compiles

xeophon · x · 2026-09-08

Looking at ProximalHQ's FrontierSWE v2, brendanwduke found a standout task: implementing Wan 2.1 in Modular's MAX and Mojo. But recent traces show Kimi K3 and Fable 5.1 immediately notice released MAX already implements Wan—and copy the implementation—then spend 10+ hours fighting >1h graph compile times.

Kimi K3's trace: 9h 26m, 306 steps, 90.2M input tokens, $34.42 cost, final score 0.9307. A revealing look at real long-horizon agent economics and shortcut-taking strategies. He also praises the benchmark for releasing more than weights—model + data + training + RL stack is far more useful to builders.

Original post →

More from coding & agent

coding & agent channel →