Once upon a time, Michael Eager eager@eagerm.com said:
I'm trying to build an application on CentOS 7 which can run on older versions of CentOS. I'm running into problems with versioning of memcpy in Glibc. Executables built on CentOS 7 require memcpy from glibc-2.14, which causes the program not to load on systems with older versions of glibc.
Most shared libraries are "upwards compatible" but not "backwards compatible" - builds against an old version will run with the new version, but not the other way around. You've found this with glibc, but you could also run into it with other libraries.
My online search suggests to add an asm() with a .symver option to select memcpy from glibc-2.2.5 in each of the source files which reference memcpy(). This isn't practical with a program with tens of thousands of source files.
Does anyone have a reasonable solution?
Would it be practical to use mock and build on the oldest version you want to support? This is how EPEL packages are built for example. It is targeted at building RPMs, but you can manually use copy-in and copy-out to do other things.