Possible 3.13.0 issue around fragments

[mattpilott]

Describe the bug
Upon updating to 3.13.0 I'm now seeing the following error, which seems to be related to transitions and slots (possibly)

Logs
Unhandled Promise Rejection: TypeError: undefined is not an object (evaluating 'intro.$$.fragment')

To Reproduce
https://svelte.dev/repl/a8d760c0fe474b238a07d684be0c39fe?version=3.13.0

Stacktraces
If you have a stack trace to include, we recommend putting inside a <details> block for the sake of the thread's readability:

Stack trace

[Error] Unhandled Promise Rejection: TypeError: undefined is not an object (evaluating 'intro.$$.fragment')
intro (Anonymous Script 3 (line 1065))
transition_in (Anonymous Script 3 (line 285))
intro (Anonymous Script 3 (line 826))
transition_in (Anonymous Script 3 (line 285))
update (Anonymous Script 3 (line 890))
update (Anonymous Script 3 (line 248))
flush (Anonymous Script 3 (line 222))
promiseReactionJob

Information about your Svelte project:

• Your browser and the version: Safari 13, Chrome 78, Firefox 70

• Your operating system: macOS 10.15.1

• Svelte version 3.13.0

• Whether your project uses Webpack or Rollup: Rollup

Severity
Crashing the thread and requires downgrading to 3.12.1

[Conduitry]

This is a return of the same issue as #2212, which I had fixed pre-3.0 but which apparently returned in the codegen refactor.

[mattpilott]

🤞 Fingers crossed hopefully its a quickish fix

[larryosborn]

I'm having a similar issue, but have a hard time reproducing in a stand-alone REPL. My component named Claim.svelte will result in TypeError: undefined is not an object (evaluating 'claim.$$.fragment').

Renaming it to something else like Claim2.svelte fixes the error. It looks like claim is used frequently in the svelte source. This issue appeared when updated to 3.13.0.

[Conduitry]

Yup, that's the same issue. I have a PR open to make a necessary fix to an upstream library, and will open one here once that's been released.

[Conduitry]

Fixed in 3.14.1 - https://svelte.dev/repl/a8d760c0fe474b238a07d684be0c39fe?version=3.14.1 - Thanks!