I remember I struggled with broken dynamic linking from bringing in binaries from the outside. I needed an entire build-chain from the same build and then build my way up with source packages (you have them around in gentoo) in my system until i reached portage. And then used emerge to recompile the buildchain twice so it was compatible with my system again.
Haha both of course. Young me was intrigued by this great puzzle of getting the system back up. Much quicker than a reinstall, too! At the same time it was one of the Gentoo moments that made me switch to Arch and Manjaro later. I certainly learned a lot with Gentoo but it was also a fragile timesink.