<p dir="auto">The following code fails to parse:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="import {a} from 'B';

export let OBJ = {
    *[Symbol.iterator]() {},
};

export class CLASS {
    *[Symbol.iterator]() {}
}"><pre class="notranslate"><code class="notranslate">import {a} from 'B';

export let OBJ = {
    *[Symbol.iterator]() {},
};

export class CLASS {
    *[Symbol.iterator]() {}
}
</code></pre></div>
<p dir="auto">The error is: "repl: undefined does not match type Pattern".</p>
<p dir="auto">Removing the <code class="notranslate">import</code> fixes it. Removing any of the two <code class="notranslate">Symbol.iterator</code> mentions fixes it. Replacing ONE of the two <code class="notranslate">Symbol.iterator</code> by a <code class="notranslate">get [Symbol.iterator]() { return function* () { ... }; }</code> fixes it. Removing the export on OBJ fixes it. Replacing OBJ by its own class fixes it.</p>
<p dir="auto">This is the smallest example that I could reduce our code to.</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="import foo from 'bar';
(function* () {});"><pre class="notranslate"><code class="notranslate">import foo from 'bar';
(function* () {});
</code></pre></div>
<p dir="auto">Compiling this raises <code class="notranslate">AssertionError: test.js: undefined does not match type Pattern</code></p>