What happened?

In Qwen Code v0.15.3, when NO_COLOR=1 is set and the interactive CLI is launched in a sufficiently wide terminal, the app crashes while rendering the welcome Header.

Reproduction command:

NO_COLOR=1 qwen --sandbox=false --approval-mode=default

Reproduction conditions:

• NO_COLOR=1
• An interactive terminal
• A terminal width large enough to show the ASCII logo, for example 180 columns

Additional observation:

In a narrower terminal, for example 80 columns, the Header does not render the ASCII logo, so this crash path is not triggered.

Actual output

The following output was captured from a tmux session using a 180x40 terminal:

  ERROR  Invalid number of stops (< 2)

 file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:426308:17

 - TinyGradient (file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:426308:17)
 - module2.exports (file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:426480:14)
 - InitGradient (file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:426494:33)
 - Gradient (file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:507970:51)
 - react-stack-bottom-frame (file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:323023:20)
 - renderWithHooks (file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:313859:24)
 - updateFunctionComponent (file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:316308:21)
 - beginWork (file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:317293:20)
 - runWithFiberInDEV (file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:312695:72)
 - performUnitOfWork (file:///Users/yiliang/.qwen-code-0.15.3-global/lib/node_modules/@qwen-code/qwen-code/cli.js:320780:82)

Screenshot

A screenshot of the same tmux error can be added here if needed.

What did you expect to happen?

When NO_COLOR=1 is set, the CLI should disable color/gradient output while still starting normally and rendering a plain-text interface.

If the active theme does not provide valid gradient colors, components should fall back to plain <Text> rendering instead of passing an empty array to ink-gradient.

Anything else we need to know?

Initial code investigation:

• NoColorTheme sets ui.gradient to [].
• Header uses theme.ui.gradient || fallback.
• Empty arrays are truthy in JavaScript, so the fallback is not used.
• As a result, <Gradient colors={[]}> reaches ink-gradient / gradient-string and throws Invalid number of stops (< 2).

Relevant code paths:

• packages/cli/src/ui/themes/no-color.ts
• packages/cli/src/ui/components/Header.tsx
• packages/cli/src/ui/components/StatsDisplay.tsx has a similar gradient length check and should also be reviewed for length >= 2.

Client information

Qwen Code v0.15.3
Model: nvidia/nemotron-3-super-120b-a12b:free
Fast Model: coder-model
Auth: openai
Platform: darwin x64 (24.6.0)
Node.js: v22.20.0
Session: 6e1fb393-6500-43ed-84fb-2118321cb96f
Git commit: dad983203