alt Hacker News> If you had a hermetically sealed code base that just happened to coincide line for line with the codebase for GCC, it would still be a copy.
If you somehow actually randomly produce the same code without a reference, it's not a copy and doesn't violate copyright. You're going to get sued and lose, but platonically, you're in the clear. If it's merely somewhat similar, then you're probably in the clear in practice too: it gets very easy very fast to argue that the similarities are structural consequences of the uncopyrightable parts of the functionality.
> The actual meaning of a "clean room implementation" is that it is derived from an API and not from an implementation (I am simplifying slightly).
This is almost the opposite of correct. A clean room implementation's dirty phase produces a specification that is allowed to include uncopyrightable implementation details. It is NOT defined as producing an API, and if you produce an API spec that matches the original too closely, you might have just dirtied your process by including copyrightable parts of the shape of the API in the spec. Google vs Oracle made this more annoying than it used to be.
> Whether the reimplementation is actually a "new implementation" is a subjective but empirical question that basically hinges on how similar the new codebase is to the old one. If it's too similar, it's a copy.
If you follow CRRE, it's not a copy, full stop, even if it's somehow 1:1 identical. It's going to be JUDGED as a copy, because substantial similarity for nontrivial amounts of code means that you almost certainly stepped outside of the clean room process and it no longer functions as a defense, but if you did follow CRRE, then it's platonically not a copy.
> What the chardet maintainers have done here is legally very irresponsible.
I agree with this, but it's probably not as dramatic as you think it is. There was an issue with a free Japanese font/typeface a decade or two ago that was accused of mechanically (rather than manually) copying the outlines of a commercial Japanese font. Typeface outlines aren't copyrightable in the US or Japan, but they are in some parts of Europe, and the exact structure of a given font is copyrightable everywhere (e.g. the vector data or bitmap field for a digital typeface, as opposed to the idea of its shape). What was the outcome of this problem? Distros stopped shipping the font and replaced it with something vaguely compatible. Was the font actually infringing? Probably not, but better safe than sorry.
> If you somehow actually randomly produce the same code without a reference, it's not a copy and doesn't violate copyright.
I don't believe this, and I doubt that the sense of copying in copyright law is so literal. For instance, if I generated the exact text of a novel by looking for hash collisions, or by producing random strings of letters, or by hammering the middle button on my phone's autosuggestion keyboard, I would still have produced a copy and I would not be safe to distribute it. There need not have been any copy anywhere near me for this to happen. Whether it is likely or not depends on the technique used - naive techniques make this very unlikely, but techniques can improve.
It is also true that similarity does not imply copying - if you and I take an identical photograph of the same skyline, I have not copied you and you have not copied me, we have just fixed the same intangible scene into a medium. The true subjective test for copying is probably quite nuanced, I am not sure whether it is triggered in this case, but I don't think "clean room LLMs" are a panacea either.
> dirty phase produces a specification ... it is NOT defined as producing an API
This does not really sound like "the opposite of correct". APIs are usually not copyrightable, the truth is of course more complicated, if you are happy to replace "API" with "uncopyrightable specification" then we can probably agree and move on.
> it's probably not as dramatic as you think it is
In reality I am very cynical and think nothing will come of this, even if there are verbatim snippets in the produced code. People don't really care very much, and copyright cases that aren't predicated on millions of dollars do not survive the court system very long.