---
title: 'Software Daily Summary: What Happened on October 10, 2026'
headline: QupKake geometry runs fail with gfortran 16 at -O3
description: An Apple Silicon guide details the compiler issue, installation choices
  and batch-processing speed.
url: https://thebench.bio/news/software/2026-10-10
topic: software
date: '2026-10-10'
covers:
- '2026-10-10'
date_published: '2026-10-10T12:01:05Z'
date_modified: '2026-10-11T00:01:25Z'
sources: 1
publisher: The Bench (thebench.bio)
---

# Software Daily Summary: What Happened on October 10, 2026

**QupKake geometry runs fail with gfortran 16 at -O3**

An Apple Silicon guide details the compiler issue, installation choices and batch-processing speed.

## Today in brief

In tests for an Apple Silicon QupKake setup, geometry optimization failed with gfortran 16 and xtb 6.4.1 at -O3, while version checks and single-point energy calculations succeeded. [1] The author reports correct results at -O2 and -O0, and suggests the failure could stem from a gfortran 16 optimizer issue or undefined behavior in older xtb code. [1]

## Also worth knowing

- The guide recommends conda-forge, PyTorch 2.1 and a Fortran format-descriptor patch. It reports processing about 4,600 drug-like molecules in 4.5 hours on 22 cores. [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/>