Multiple Glibc Libraries on a Single Host

Multiple glibc libraries on a single host

It is very possible to have multiple versions of glibc on the same system (we do that every day).

However, you need to know that glibc consists of many pieces (200+ shared libraries) which all must match. One of the pieces is ld-linux.so.2, and it must match libc.so.6, or you'll see the errors you are seeing.

The absolute path to ld-linux.so.2 is hard-coded into the executable at link time, and can not be easily changed after the link is done (Update: can be done with patchelf; see this answer below).

To build an executable that will work with the new glibc, do this:

g++ main.o -o myapp ... \
   -Wl,--rpath=/path/to/newglibc \
   -Wl,--dynamic-linker=/path/to/newglibc/ld-linux.so.2

The -rpath linker option will make the runtime loader search for libraries in /path/to/newglibc (so you wouldn't have to set LD_LIBRARY_PATH before running it), and the -dynamic-linker option will "bake" path to correct ld-linux.so.2 into the application.

If you can't relink the myapp application (e.g. because it is a third-party binary), not all is lost, but it gets trickier. One solution is to set a proper chroot environment for it. Another possibility is to use rtldi and a binary editor. Update: or you can use patchelf.

How to install multiple versions of glibc?

If you just want the dynamic libraries from the other version of glibc you can simply use LD_LIBRARY_PATH. But if you want to fully use the other version you need to compile against the other version to get the static parts. And you might want to compile the other version of glibc as well to get all the hardcoded paths to point to your installation directory for loading datafiles and plugins (for NSS and gconv). Using --prefix=/usr/glibc2.3.4 will also set the soname of the dynamic loader to /usr/glibc2.3.4/lib/ld-linux.so.2 (or something similar depending on your architecture) which will be hardcoded into every program linked against it.

Removing glibc dependency when compiling with gcc

Is it possible to compile a program using gcc without depending on glibc?

Yes, there are alternative libc versions, such as Musl, uClibc, dietLibc, etc. See their documentation on how to use them.

Your problem does not appear to be a GLIBC dependency, but rather a mismatch between your build and your target hosts. In particular, your target has older GLIBC than your build host.

The easiest to solution for that problem is to build on an old-enough system -- your binary will run on anything that is as-old or newer. You could do that inside a VM or in a docker container, so you don't have to downgrade your main system.

You could also link your program statically (add -static flag), but beware -- for many non-trivial programs this will make your binary less portable.

Multiple Glibc Libraries on a Single Host