Debian Sid now include glibc 2.5. Compiled programs on Debian Sid may or may not run on distro with older libc. If this command display something it means that the executable contains glibc 2.5 specific calls:
objdump -T myexec | grep GLIBC_2.5
To list 2.5 specific primitive just do:
objdump -T /lib/libc.so.6 | grep GLIBC_2.5
Note that libc 2.5 do not add many symbols. See the progression:
$ objdump -T /lib/libc.so.6 | grep GLIBC_2.0 | wc -l 1318 $ objdump -T /lib/libc.so.6 | grep GLIBC_2.1 | wc -l 409 $ objdump -T /lib/libc.so.6 | grep GLIBC_2.2 | wc -l 195 $ objdump -T /lib/libc.so.6 | grep GLIBC_2.3 | wc -l 160 $ objdump -T /lib/libc.so.6 | grep GLIBC_2.4 | wc -l 77 $ objdump -T /lib/libc.so.6 | grep GLIBC_2.5 | wc -l 18
Unfortunnatly debian package will require libc 2.5 even if 2.5 extension are not used. See this extract from #debian-glibc:
[me] [french sorry for my english] Does shlibdeps handle glibc symbol version ? For example if an executable only use GLIBC_2.0 symbols, will it required libc >= 2.5 or only lib >= 2.0 ?
[Clint] no, it's not that smart yet
[me] May be one day ? As it already been discussed ?
[Clint] it's been discussed, but people usually say that it's not worth the effort
[me] ok. Thanks !
[Clint] if you want to write a patch to do it though, that might be useful
[me] Hu ! I would glad to but I guess I would have to learn perl first :-/