"'Abort, Retry, Fail?' was the phrase some wormdog scrawled next to the door of the Edit Universe project room. And when the new dataspinners started working, fabricating their worlds on the huge organic comp systems, we'd remind them: if you see this message, always choose 'Retry." – Bad'l Ron, Wakener, "Morgan Polysoft"

From scratch means if I am on a fresh install of whatever OS they are targetting and have a compiler (compiler, not build tool, so rustc, not cargo) of the language they use I can build the project without having to install any dependencies.

Is developing a software "from scratch" defined somewhere?

Seems like you arbitrarily draw the line. rustc but not cargo?

Even if you don't use any libraries, cargo is a useful tool. And if you reject tools, what editor/IDE would you code in?

I'm not saying anything about coding, I'm saying that if you code a thing in whatever language (let's say Ada) and I have a fresh install of an operating system (let's say Debian) and a compiler for the language you use (like the GCC Ada compiler) I should be able to compile your script into a program without having to install additional dependencies (like Alire).

I'd say that's more describing "without (library) dependencies".

I'm not in the construction business, but I guess if you build a house from the ground up, that means you're not building on top of some existing structure, but you might still be using prefabricated elements.

I'd put the line here: whether ground work is used that was laid for editors, as opposed to general programming. If the thing that they are making (an editor) does not contain editor-specific prefabricated parts, then all the editor-specific work was still made from the ground up.

Real programmers use butterflies. https://xkcd.com/378/