1hr+ for a general update* (following the guide. Pre-kernel)
On a more serious note, gentoo is fun… On competent hardware. This is a 4 core Celeron N2940 with 4gb of RAM.
*emerge --ask --verbose --update --deep --changed-use @world is too long to type…
If you set USE flags on a package (or globally, effecting a package) portage seamlessly switches to compile that package with those different USE flags from the defaults that the binaries are available with. It’s not all or none. You can simply omit the -g flag if you want to compile anyway.
That’s true. Though typically that’ll only be where you have changed something requiring a change to configs for USE flags or keywords.