Right now I am running a virtual machine with older debian and compile everything there but it is kinda slow.

This is probably the simplest and easiest solution :)

But, apparently you can have multiple version on glibc on the same machine by managing LD_LIBRARY_PATH

The Answer Guy 48: Multiple Concurrently Installed Version of glibc

So you'd have to install old version of glibc on your dev-machine ( 200+ pieces of it ), recompile perl/PAR::Packer and any other modules you need to use this older version of glibc ....

Either way its path management....:)