Comment 0 for bug 1317136

Trusty's gdb and ltrace have lost the helpful error details when ptrace attach fails. Compare to strace:

$ strace -p 1
strace: attach: ptrace(PTRACE_ATTACH, ...): Operation not permitted
Could not attach to process. If your uid matches the uid of the target
process, check the setting of /proc/sys/kernel/yama/ptrace_scope, or try
again as the root user. For more details, see /etc/sysctl.d/10-ptrace.conf

$ gdb -p 1
GNU gdb (Ubuntu 7.7-0ubuntu3) 7.7
...
Attaching to process 1
ptrace: Operation not permitted.

$ ltrace -p 1
Cannot attach to pid 1: Operation not permitted

In Precise ltrace has the correct error (though gdb is still missing it -- this was lost quite some time ago it seems):

$ ltrace -p 1
Could not attach to process. If your uid matches the uid of the target
process, check the setting of /proc/sys/kernel/yama/ptrace_scope, or try
again as the root user. For more details, see /etc/sysctl.d/10-ptrace.conf
Cannot attach to pid 1: Operation not permitted