In principle you can patch your binary to accept the old local version, though I don't remember ever getting it to work right. Anyway here it is for the brave or foolhardy, here's the gist:
Oh, sure, rpath/runpath shenanigans will work in some situations but then you'll be tempted to make such shenanigans work in all situations and then the madness will get you...
To save everyone a click here are the first two bullet points from Exhibit A:
* If an executable has `RPATH` (a.k.a. `DT_RPATH`) set but a shared library that is a (direct or indirect(?)) dependency of that executable has `RUNPATH` (a.k.a. `DT_RUNPATH`) set then the executable's `RPATH` is ignored!
* This means a shared library dependency can "force" loading of an incompatible [(for the executable)] dependency version in certain situations. [...]
Further nuances regarding LD_LIBRARY_PATH can be found in Exhibit B but I can feel the madness clawing at me again so will stop here. :)
2. Replace libc.so with a fake library that has the right version symbol with a version script
e.g. version.map
GLIBC_2.29 {
global:
*;
};
With an empty fake_libc.c
`gcc -shared -fPIC -Wl,--version-script=version.map,-soname,libc.so.6 -o libc.so.6 fake_libc.c`
3. Hope that you can still point the symbols back to the real libc (either by writing a giant pile of dlsym C code, or some other way, I'm unclear on this part)
Ideally glibc would stop checking the version if it's not actually marked as needed by any symbol, not sure why it doesn't (technically it's the same thing normally, so performance?).
So you can do e.g. `patchelf --remove-needed-version libm.so.6 GLIBC_2.29 ./mybinary` instead of replacing glibc wholesale (step 2 and 3) and assuming all of used glibc by the executable is ABI compatible this will just work (it's worked for a small binary for me, YMMV).
