How to get permission to debug postgres?

I have a system that uses C methods as functions in a Postgres database. When I try to run gdb with my user account I get this: ptrace: Operation not permitted

It looks like a permission thing. It seemed to work when I ran gdb as the "postgres" user. I would like to continue running postgres as the "postgres" user and not have to su postgres when I want to debug. Can I somehow grant my user account "ptrace" permission 开发者_如何学编程for the process in question? Adding myself to the "postgres" group didn't seem to help.

EDIT: I found this on the ptrace man page:

EPERM  The specified process cannot be traced.  This could  be  because
              the  parent has insufficient privileges (the required capability
              is CAP_SYS_PTRACE); non-root processes  cannot  trace  processes
              that  they  cannot  send  signals  to or those running set-user-
              ID/set-group-ID programs, for obvious  reasons.   Alternatively,
              the process may already be being traced, or be init(8) (PID 1).

So how can I give CAP_SYS_TRACE privileges to my user?

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It seems CAP_SYS_TRACE is controlled by LIDS which may or may not be installed on your computer.

If you are doing heavy development on postgres you might prefer to run an instance of postgres under your own account - this is what I do with a number of servers I work on.