nixOS is built around hashing the outputs of its builds, so you can verify if a build produces the expected output given the same inputs. The reason nixOS patch

nixOS is built around hashing the outputs of its builds, so you can verify if a build produces the expected output given the same inputs. The reason nixOS patches binaries is so that they can actually find the shared objects they expect when they are not stored in /usr/lib. Since every build output gets its own unique path, this allows for a binary to link against two slightly different versions of the same library, which in practice is never an issue one needs to resolve. However, a more practical issue this solves is that you can have a single sysroot with two binaries that need two slightly different versions of the same library.