Each executable or shared library built with Red Hat Enterprise Linux Server 6 or later is assigned a unique identification 160-bit SHA-1 string, generated as a checksum of selected parts of the binary. This allows two builds of the same program on the same host to always produce consistent build-ids and binary content.
Display the build-id of a binary with the following command:
$ eu-readelf -n /bin/bash
Note section [ 3] '.note.gnu.build-id' of 36 bytes at offset 0x274:
Owner Data size Type
GNU 20 GNU_BUILD_ID
Build ID: efdd0b5e69b0742fa5e5bad0771df4d1df2459d1