svelte.ts files webpack serve error

[philippone]

When running a webpack application with svelte.ts files the webpack build is working (and seems to be running correctly) but webpack serve producing the following error:

/workspace/test/template-webpack/node_modules/loader-runner/lib/LoaderRunner.js:146
                if(isError) throw e;
                            ^

TypeError: Cannot read properties of null (reading 'startsWith')
    at contextifySourceUrl (/Users/philipp.schardt/workspace/test/template-webpack/node_modules/webpack/lib/NormalModule.js:143:13)
    at /Users/philipp.schardt/workspace/test/template-webpack/node_modules/webpack/lib/NormalModule.js:173:3
    at Array.map (<anonymous>)
    at contextifySourceMap (/Users/philipp.schardt/workspace/test/template-webpack/node_modules/webpack/lib/NormalModule.js:172:39)
    at NormalModule.createSource (/Users/philipp.schardt/workspace/test/template-webpack/node_modules/webpack/lib/NormalModule.js:844:5)
    at processResult (/Users/philipp.schardt/workspace/test/template-webpack/node_modules/webpack/lib/NormalModule.js:928:24)
    at /Users/philipp.schardt/workspace/test/template-webpack/node_modules/webpack/lib/NormalModule.js:1034:5
    at /Users/philipp.schardt/workspace/test/template-webpack/node_modules/loader-runner/lib/LoaderRunner.js:407:3
    at iterateNormalLoaders (/Users/philipp.schardt/workspace/test/template-webpack/node_modules/loader-runner/lib/LoaderRunner.js:233:10)
    at iterateNormalLoaders (/Users/philipp.schardt/workspace/test/template-webpack/node_modules/loader-runner/lib/LoaderRunner.js:240:10)

Reproduction repo

• npm run build is working correctly
• npm run dev produces the error
• Dev task is working when removing the import of test.svelte in App.svelte

Btw, I guess the alias in webpack config in the README should be removed for Svelte 5.
svelte/src/runtime seems to be removed.

alias: {
      svelte: path.resolve('node_modules', 'svelte/src/runtime') // Svelte 3: path.resolve('node_modules', 'svelte')
    },