Check for cmp and diff in configure
Seen somewhere in the configure output of babeltrace on a fresh centos 8 container:
checking for a working dd... ./configure: line 9826: cmp: command not found checking if gcc supports -fno-rtti -fno-exceptions... ./configure: line 11790: diff: command not found
The configure keeps going, I think the consequence may simply be that the results of these checks are inaccurate.
For correctness, if these tools (cmd and diff) are used, there should be something that checks that they exist before using them.