#26201·scipy

BUG: <Qhull option error with the "." character when compiling examples with Sphinx>

Author: 4nileCreated Sep 17, 2026Updated Sep 18, 2026
Labelsdefectscipy.spatial

Describe your issue.

Hi!

I am building a library that uses quite extensively the SciPy implementations of QHull and have run into an error as I was compiling the examples in my documentation. When I run my code from my usual IDE, which is Spyder, or from a console, I have no issue, but when running the same code specifically as Sphinx compiles, the dot character (for example in option "Cn") seems to not be interpreted in the same way and raises an error that ". is an unknown option", instead of reading the decimal number using that dot.

The error message below is specifically the error thrown by Sphinx as the example file did not compile properly. In spyder or from a console I have no issue.

Reproducing Code Example

python
import numpy as np
from scipy.spatial import Delaunay

pts = np.random.default_rng().uniform(-5,5,(20,3))
size = np.ptp(pts, axis=0)
dt = Delaunay(pts, qhull_options="Qt Qbb Qc Qz Q8 Q14 "
              + "C" + str(1./10/size.mean())
              + " C-" + str(1./8/size.mean()))

Error message

bash
Traceback (most recent call last):
      File "<I am voluntarily hiding the full path here as it is a working folder for my job>\examples\api\plot_test_qhull.py", line 15, in <module>
        dt = Delaunay(pts, qhull_options="Qt Qbb Qc Qz Q8 Q14 "
                      + "C" + str(1./10/size.mean())
                      + " C-" + str(1./8/size.mean()))
      File "scipy/spatial/_qhull.pyx", line 1889, in scipy.spatial._qhull.Delaunay.__init__
      File "scipy/spatial/_qhull.pyx", line 357, in scipy.spatial._qhull._Qhull.__init__
    scipy.spatial._qhull.QhullError: QH7094 qhull option warning: unknown option '.'(2e)
    QH7036 qhull option warning: missing space after option '.'(2e), reserved for sub-options, ignoring '.' options to next space
    QH7094 qhull option warning: unknown option '.'(2e)
    QH7036 qhull option warning: missing space after option '.'(2e), reserved for sub-options, ignoring '.' options to next space
    QH6035 qhull option error: see previous warnings, use 'Qw' to override: 'qhull d Qz Q14 Q8 C-0.013908721529890731 Qt C0.011126977223912584 Qc Qbb' (last offset 46)

    While executing:  | qhull d Qz Q14 Q8 C-0.013908721529890731 Qt C0.011126977223912584 Qc Qbb
    Options selected for Qhull 2020.2.r 2020/08/31:
      run-id 729938742  delaunay  Qz-infinity-point  Q14-merge-pinched-vertices
      Q8-no-near-inside  Centrum-premerge-  0  Qtriangulate  Centrum-postmerge  0
      Qcoplanar-keep  Qbbound-last  _maxoutside  0

SciPy/NumPy/Python version and system information

bash
1.18.1 2.4.6 sys.version_info(major=3, minor=14, micro=0, releaselevel='final', serial=0)
{
  "Compilers": {
    "c": {
      "name": "clang-cl",
      "linker": "lld-link",
      "version": "21.1.8",
      "commands": "clang-cl",
      "linker args": "-Wl,-defaultlib:D:/bld/scipy-split_1789136384949/_build_env/lib/clang/21/lib/windows/clang_rt.builtins-x86_64.lib"
    },
    "cython": {
      "name": "cython",
      "linker": "cython",
      "version": "3.3.0",
      "commands": "cython"
    },
    "c++": {
      "name": "clang-cl",
      "linker": "lld-link",
      "version": "21.1.8",
      "commands": "clang-cl",
      "linker args": "-Wl,-defaultlib:D:/bld/scipy-split_1789136384949/_build_env/lib/clang/21/lib/windows/clang_rt.builtins-x86_64.lib"
    },
    "fortran": {
      "name": "llvm-flang",
      "linker": "lld-link",
      "version": "21.1.8",
      "commands": "flang.exe",
      "args": "-D_CRT_SECURE_NO_WARNINGS, -fms-runtime-lib=dll, -fuse-ld=lld, -IC:<I am voluntarily hiding the full path here as it is a working folder for my job>/.pixi/envs/default/Library/include",
      "linker args": "-Wl,-defaultlib:D:/bld/scipy-split_1789136384949/_build_env/lib/clang/21/lib/windows/clang_rt.builtins-x86_64.lib, -D_CRT_SECURE_NO_WARNINGS, -fms-runtime-lib=dll, -fuse-ld=lld, -IC:<I am voluntarily hiding the full path here as it is a working folder for my job>/.pixi/envs/default/Library/include"
    },
    "pythran": {
      "version": "0.19.0",
      "include directory": "../../_h_env/Lib/site-packages/pythran"
    }
  },
  "Machine Information": {
    "host": {
      "cpu": "x86_64",
      "family": "x86_64",
      "endian": "little",
      "system": "windows"
    },
    "build": {
      "cpu": "x86_64",
      "family": "x86_64",
      "endian": "little",
      "system": "windows"
    },
    "cross-compiled": false
  },
  "Build Dependencies": {
    "blas": {
      "name": "blas",
      "found": true,
      "version": "3.9.0",
      "detection method": "pkgconfig",
      "include directory": "<I am voluntarily hiding the full path here as it is a working folder for my job>/.pixi/envs/default/Library/include",
      "lib directory": "<I am voluntarily hiding the full path here as it is a working folder for my job>/.pixi/envs/default/Library/lib",
      "openblas configuration": "unknown",
      "pc file directory": "<I am voluntarily hiding the full path here as it is a working folder for my job>/.pixi/envs/default/Library/lib/pkgconfig",
      "has ilp64": false,
      "cython blas ilp64": false
    },
    "lapack": {
      "name": "lapack",
      "found": true,
      "version": "3.9.0",
      "detection method": "pkgconfig",
      "include directory": "<I am voluntarily hiding the full path here as it is a working folder for my job>/.pixi/envs/default/Library/include",
      "lib directory": "<I am voluntarily hiding the full path here as it is a working folder for my job>/.pixi/envs/default/Library/lib",
      "openblas configuration": "unknown",
      "pc file directory": "<I am voluntarily hiding the full path here as it is a working folder for my job>/.pixi/envs/default/Library/lib/pkgconfig",
      "has ilp64": false
    },
    "pybind11": {
      "name": "pybind11",
      "version": "3.1.0",
      "detection method": "pkgconfig",
      "include directory": "<I am voluntarily hiding the full path here as it is a working folder for my job>/.pixi/envs/default/Library/include"
    }
  },
  "Python Information": {
    "path": "<I am voluntarily hiding the full path here as it is a working folder for my job>/.pixi/envs/default/python.exe",
    "version": "3.14"
  }
}
<I am voluntarily hiding the full path here as it is a working folder for my job>\.pixi\envs\default\Lib\site-packages\scipy\__config__.py:167: UserWarning: Install `pyyaml` for better output
  warnings.warn("Install `pyyaml` for better output", stacklevel=1)