Installing Claude Desktop on Ubuntu 20.04 / Mint 20 (glibc 2.31)
Anthropic’s official Claude Desktop .deb declares libc6 (>= 2.34), which
means Ubuntu 22.04+ / Mint 21+. On Mint 20.3 (focal, glibc 2.31) apt refuses
to install it. It turns out that dependency is an overstatement, and the app
runs fine on glibc 2.31 once you know which three files actually need 2.34.

