Support multiple pixi versions via build backend version range#71
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Support multiple pixi versions via build backend version range#71
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pixi-build-cmake version changes: - 0.3.4 requires build API v2 (pixi 0.54-0.62) - 0.3.8 requires build API v4 (pixi 0.63+) This change is required for ZEST to use SlaterGPU as a source dependency with pixi 0.63+. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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I figured out in the molecularGSM repo how to configure for multiple potential backend versions and let pixi decide which is compatible with pixi's own version. I should do something analogous here |
Instead of pinning ==0.3.8 (which requires pixi >=0.63), use the range >=0.3.6,<=0.3.8 so pixi automatically selects the correct backend API version for the user's installed pixi. This matches the approach used in molecularGSM and avoids forcing all collaborators to upgrade pixi simultaneously. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Extract the minimum pixi version from requires-pixi in pixi.toml instead of hardcoding v0.54.0. Regular builds test against the minimum supported version; monthly scheduled builds test against the latest pixi to catch regressions early. Also scope push/PR triggers to the main branch. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
joshkamm
changed the title
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cc @piwonis @DuttaS12 — This PR should fix the "could not initialize the build-backend" error you both ran into when installing with a newer pixi version. Instead of pinning to a single A corresponding ZEST PR with the same change will follow once this is merged. |
DuttaS12
approved these changes
Feb 24, 2026
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Summary
pixi-build-cmakefrom==0.3.4to>=0.3.6,<=0.3.8, allowing pixi to auto-select the correct backend API versionrequires-pixifrom>=0.54to>=0.60.0pixi.tomlinstead of hardcodingv0.54.0Context
Users installing with pixi >= 0.63 (e.g. fresh installs on Perlmutter) hit a "could not initialize the build-backend" error because
pixi-build-cmake==0.3.4only supports build API v2, while pixi 0.63+ requires API v4. Instead of pinning to the new version (which would break older pixi), we use a version range so pixi resolves the compatible backend automatically. This matches the approach used in molecularGSM.Note: A corresponding ZEST PR will follow once this is merged, since ZEST also pins
==0.3.4and needs the same update (both for its own build and because it pulls SlaterGPU as a source dependency).Test plan
pixi installsucceeds on pixi 0.62.2pixi installsucceeds on pixi 0.63.2pixi run test-slaterpasses with this SlaterGPU as local path dependency on pixi 0.63.2 (CI: -1.16064818)