Misc. bug: WebUI (server) crash after streeaming response

[stduhpf]

Name and Version

version: 6219 (1bc664a)
built with MSVC 19.44.35209.0 for x64

Operating systems

No response

Which llama.cpp modules do you know to be affected?

llama-server

Command line

cd tools/server/webui
npm i
npm run dev

Problem description & steps to reproduce

Start server, go to webui with any browser (tried chrome and firefox), type any prompt and send it.

The response streams as expected, but once it's done generating, it dissapears with a popup saying:

can't access property "delta", ie.choices[0] is undefined (firefox), or cannot read the properties of undefined (reading 'delta') (chrome)

First Bad Commit

Didn't bother doing a bisect

Relevant log output

in devtools:


(index):250 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'delta')
    at j ((index):250:3415)
    at async at ((index):250:4503)
    at async L ((index):604:11275)


That's not very helpful, so I started the webui in dev mode, and I got this:

app.context.tsx:258 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'delta')
    at generateMessage (app.context.tsx:258:47)
    at async replaceMessageAndGenerate (app.context.tsx:381:5)
    at async handleRegenerateMessage (ChatScreen.tsx:180:5)

[stduhpf]

The fix is very easy though, just adding a ? character in app.context.tsx, line 258 seems to work

[ddh0]

I also have this issue after updating to the latest master (build: 6220 (5682a374)).

[imweijh]

build/bin/llama-server -hf ggml-org/gpt-oss-120b-GGUF -c 0 -fa --jinja --chat-template-file ~/gpt-oss-chat-template.jinja

Server Info
Model: ggml-org_gpt-oss-120b-GGUF_gpt-oss-120b-mxfp4-00001-of-00003.gguf
Build: b6220-5682a374

have the same error:
Cannot read properties of undefined (reading 'delta')

git switch b6218 then rebuild all is ok

[TeoZosa]

FYI @stduhpf @ddh0 @imweijh cc @h9j6k, this regression was introduced in #15444.

I pushed the same fix @stduhpf mentioned in #15464. Once I can get reliable network to rebuild the WebUI files then hopefully we can get this resolved.

EDIT: Just noticed #15462, feel free to ignore the above PR.