gdb does not stop when piping the command

Question

When running the usual way, gdb stops as expected:

(gdb) break main
(gdb) run
Starting program ...
Breakpoint 1, main ...

when running while piping, gdb never stops:

(gdb) run | cat
Starting program: /home/sds/z | cat
...
During startup program exited normally.
(gdb)

How do I debug program behavior when piping?

my setup:

$ gdb --version
GNU gdb (GDB) Amazon Linux (7.6.1-64.33.amzn1)
$ uname -a
Linux datasci-1 4.4.19-29.55.amzn1.x86_64 #1 SMP Mon Aug 29 23:29:40 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
$ gcc --version
gcc (GCC) 4.8.3 20140911 (Red Hat 4.8.3-9)

same problem on the most recent fully updated ubuntu (16.10).

Answer 1

While input and output redirection work, you cannot use pipes to pass the output of the program you are debugging to another program; if you attempt this, GDB is likely to wind up debugging the wrong program.

https://www.sourceware.org/gdb/onlinedocs/gdb.html

Answer 2

Based on another answer :

(gdb) run > >(cat)

See Process Substitution .