{"record":{"id":"0e68058bc6ae380c","repo":"vercel/next.js","slug":"the-sassoptions-functions-option-is-not-supporte","errorCode":null,"errorMessage":"The \"sassOptions.functions\" option is not supported when using Turbopack. Custom Sass functions are only available with webpack. Please remove the \"functions\" property from your sassOptions in ${configFileName}.","messagePattern":"The \"sassOptions\\.functions\" option is not supported when using Turbopack\\. Custom Sass functions are only available with webpack\\. Please remove the \"functions\" property from your sassOptions in (.+?)\\.","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"packages/next/src/server/config.ts","lineNumber":565,"sourceCode":"    }\n  }\n\n  if (\n    result.experimental?.allowDevelopmentBuild &&\n    process.env.NODE_ENV !== 'development'\n  ) {\n    throw new Error(\n      `The experimental.allowDevelopmentBuild option requires NODE_ENV to be explicitly set to 'development'.`\n    )\n  }\n\n  // Validate sassOptions.functions is not used with Turbopack\n  if (\n    process.env.TURBOPACK &&\n    result.sassOptions &&\n    'functions' in result.sassOptions\n  ) {\n    throw new Error(\n      `The \"sassOptions.functions\" option is not supported when using Turbopack. ` +\n        `Custom Sass functions are only available with webpack. ` +\n        `Please remove the \"functions\" property from your sassOptions in ${configFileName}.`\n    )\n  }\n\n  // Validate experimental.cssChunking compatibility with the active bundler. Graph mode is\n  // Turbopack-only; strict mode and `false` (single-chunk-per-module) are webpack-only.\n  // Only validate during build/dev — `next start` doesn't pick a bundler and would otherwise\n  // see `process.env.TURBOPACK` unset and reject a valid `cssChunking: \"graph\"` config.\n  if (\n    phase !== PHASE_PRODUCTION_SERVER &&\n    phase !== PHASE_INFO &&\n    phase !== PHASE_TEST\n  ) {\n    if (result.experimental.durableUseCacheEntries && !process.env.TURBOPACK) {\n      throw new Error(\n        `\\`experimental.durableUseCacheEntries: true\\` is only supported with Turbopack. ` +","sourceCodeStart":547,"sourceCodeEnd":583,"githubUrl":"https://github.com/vercel/next.js/blob/34433fd12ee8074ea3f47af9f36255c7390d0301/packages/next/src/server/config.ts#L547-L583","documentation":"Error \"The \"sassOptions.functions\" option is not supported when using Turbopack. Custom Sass functions are only available with webpack. Please remove the \"functions\" property from your sassOptions in ${configFileName}.\" thrown in vercel/next.js.","triggerScenarios":"sassOptions.functions is configured while using Turbopack.","commonSituations":"Custom Sass functions in next.config with the default Turbopack bundler; only webpack supports them.","solutions":["Remove sassOptions.functions, or switch to webpack (next dev/build --webpack)."],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"34433fd12ee8074ea3f47af9f36255c7390d0301","analyzedAt":"2026-08-19T02:10:13.922Z","contentChangedAt":"2026-08-19T02:10:13.922Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}