---
title: 'Life Sciences Daily Summary: What Happened on October 10, 2026'
headline: QupKake guide reports geometry failures with -O3 on Apple Silicon
description: The author found that lowering compiler optimization to -O2 or -O0 avoided
  failures in geometry optimization tests.
url: https://thebench.bio/news/summaries/2026-10-10
topic: all
date: '2026-10-10'
covers:
- '2026-10-10'
date_published: '2026-10-10T12:01:17Z'
date_modified: '2026-10-10T12:01:17Z'
sources: 1
publisher: The Bench (thebench.bio)
---

# Life Sciences Daily Summary: What Happened on October 10, 2026

**QupKake guide reports geometry failures with -O3 on Apple Silicon**

The author found that lowering compiler optimization to -O2 or -O0 avoided failures in geometry optimization tests.

## Today in brief

A QupKake setup guide reports that geometry optimizations failed with gfortran 16 and xtb 6.4.1 at -O3, but worked at -O2 and -O0. [1]

## Also worth knowing

- QupKake predicts micro-pKa values using GFN2-xTB and graph neural networks. In the author's tests, gfortran 16 with xtb 6.4.1 at -O3 caused geometry optimizations to fail, while version checks and single-point energy calculations succeeded. The author did not determine the cause and suggested it could involve a gfortran 16 optimizer issue or undefined behavior in older xtb code. [1]

## Sources

1. [Building QupKake on Apple Silicon (macOS arm64)](<https://macinchem.org/2026/10/10/building-qupkake-on-apple-silicon-macos-arm64/>), Mac in Chem, 2026-10-10

---

The Bench wrote this from the reporting cited above, with a language model drafting and editing.

[1]: <https://macinchem.org/2026/10/10/building-qupkake-on-apple-silicon-macos-arm64/>