There was no Perl 5 to Perl 6 migration. Perl 6 was announced, a bunch of design work happened on it, and then it became a different language run by different people rather than a version of Perl. People are still writing Perl code extensively, and Perl 5 is still maintained.

I would expect Python to follow a similar language split. People were disappointed at how few breaking changes occurred in 2->3. If there was going to be a 3->4 migration, will be a large number of proposals to correct other deficiencies in the language.

"How bad was the migration?"

"It didn't happen"

It didn’t happen, but it still killed the language.

... I mean if you want to compare that it had exactly same problem so it is another evidence it's not something specific to Python, it's just utterly terrible way to go ahead.

Only difference is that they noticed it's a bad idea midway and went back to developing Perl 5

And I still can write "use v5.8" in my Perl script and write script that works in Centos 5 instance from 2007, if I needed to do something on legacy system, and it will work the same on latest Perl.

> because at the time Perl was more popular than Python.

I don't believe that was true at the time as P6 took like decade to decide on semantics and only then the implementations started to happen. More existing code, sure, but much of the web dev moved to PHP/Ruby and many other things to Python.

And unlike Py3 it was initially also much slower than P5, making migration kinda worthless.