I'd be happy to try and explain, but like... it's what the post is about, so I'm not sure how to explain it without saying what the post says. Is there a specific thing you're curious about? What bits didn't make sense?
Should we be alarmed that a system as error prone as incremental compilation (in any language, I remember Apple flirting with fix-and-continue with Objective-C as well) is considered mandatory to have a reasonable developer experience with Rust due to massive compilation times?
No, not really, and without actual root cause analysis it's impossible to "be alarmed" about such a thing in any informed sense of the phrase. For instance, "incremental compilation" is obviously not the only prerequisite for this bug to manifest, otherwise it probably would have been found already since it's so widely used. So it is quite necessary for multiple flaws to compound until they manifest in some particular way like this; would you also say "rain is caused solely by clouds and nothing else"?
Without any actual analysis of why this bug occurred under what particular circumstances, how it was introduced, and what failures lead to it (which is not something most programmers are good at, in my experience), you're just psyching yourself out.
