I was recently struggling to disable eldoc until I learned that this is some kind of built-in mode and that (!package eldoc :disable t) has no effect.
How can we get a list of what packages are actually installed and can be used with the !package directive?
I’ve tried the list-packages command, but this shows eldoc even though eldoc doesn’t work with !package. Additionally, it doesn’t show the flycheck package as installed when it definitely is.
I think visiting M-x list-packages is correct (although managing packages in Doom Emacs from there is discouraged, IIUC) but there is a difference between what Doom and Emacs call a built-in package.
Tangential: I don’t have the flycheck package installed. Maybe you have customized the installation of Doom Emacs?