> glibc has very good backward compatibility, with careful symbol versioning and whatnot.
Not in my experience. Working through exercises in Practical Binary Analysis, the first problem I needed to solve was running programs compiled against an older glibc on older Ubuntu on a new Ubuntu version with newer glibc, which boiled down to hunting down the glibc so from the older Ubuntu. Without it, the programs crashed on startup. That problem wasn’t even planned by the book author, but it sure was a good thematic fit. :)
Not in my experience. Working through exercises in Practical Binary Analysis, the first problem I needed to solve was running programs compiled against an older glibc on older Ubuntu on a new Ubuntu version with newer glibc, which boiled down to hunting down the glibc so from the older Ubuntu. Without it, the programs crashed on startup. That problem wasn’t even planned by the book author, but it sure was a good thematic fit. :)