I wouldn't install it, but unpack it in some work directory and refer to it via LD_LIBRARY_PATH
. Downgrading your libc6 package can be quite problematic.
Your customer should be able to supply you with their libc6 version. It might, however, be advisable to use the libc6-dbg
package which includes debug symbols. Unfortunately the 7u4
version is an older one and not available anymore.