Comment by flohofwoe

Just to add some more context. Zig cc is a wrapper around clang. It can handle cross compiling to specific glibc versions. See https://andrewkelley.me/post/zig-cc-powerful-drop-in-replace... I imagine it would help with the glibc problems they are taking about. Glibc tries to provide a backwards compatible abi.

> I think the problem in a nutshell is that it's not trivial(?) to build an executable on a modern Linux distro that links against an old glibc version number (and if it is trivial then it needs to be better communicated).

I wouldn't say it's trivial, but it's not rocket science either. Basically there are two main approaches. One is to just build inside a chroot or container with a sufficiently old distro inside. This is generally the path of least resistance because your build system doesn't really have to have any awareness of what's going on. You just build normally inside the chroot/container. The main downsides with this approach are that it's kind of wasteful (you have a whole distro's filesystem) and if you want to use a newer compiler than what the old distro in question shipped with you generally have to build it yourself inside said chroot/container.

The other main approach is to use a sysroot. gcc and clang both take an optional --sysroot parameter which is an alternative root for header and library lookups. This lets you use a compiler on the normal host, but old headers and libs. You can also bake this parameter in when compiling gcc (and also I assume clang, but less sure there) if you want a dedicated cross-toolchain.