Bug 2439654

Summary: Please include fftw3 as a build dependency / build with --with-fftw3=yes
Product: [Fedora] Fedora Reporter: Gerald Fournier <sourceforge.supply694>
Component: ngspiceAssignee: Mamoru TASAKA <mtasaka>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 43CC: mschweikardt, mtasaka
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OS: Linux   
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Fixed In Version: ngspice-45.2-3.fc43 Doc Type: ---
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Last Closed: 2026-02-22 00:44:20 UTC Type: ---
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Description Gerald Fournier 2026-02-13 07:27:33 UTC 
ngspice supports the battle-tested fftw library for fast and accurate FFT calculation. The fedora package of ngspice doesn't include fftw-devel as a BuildRequires, so the built-in and rather limited FFT routines are used (a).

Since fftw is already packaged and readily available on fedora, and is a widely used and mature library, it would be lovely if the fedora package went ahead and depended on it.

the autotools configure script should detect its availability without any changed, but you could also use --with-fftw3=yes to force it.

(a) among other things, the built in fft is limited to power-of-2 length inputs, which means zero-padding and thus an unforseen shift in the location of frequency bins in the results. It's also potentially slower than the optimized fftw library.

Reproducible: Always
Comment 1 Fedora Update System 2026-02-13 13:55:32 UTC 
FEDORA-2026-beb7bcbe93 (ngspice-45.2-3.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-beb7bcbe93
Comment 2 Gerald Fournier 2026-02-13 14:21:18 UTC 
Thank you!
Comment 3 Fedora Update System 2026-02-14 01:30:04 UTC 
FEDORA-2026-beb7bcbe93 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-beb7bcbe93`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-beb7bcbe93

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.
Comment 4 Fedora Update System 2026-02-22 00:44:20 UTC 
FEDORA-2026-beb7bcbe93 (ngspice-45.2-3.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.