Coproc within coproc supported?

[Tadeus Prastowo]

Hi!

The Bash 4.3.48 that comes shipped with Ubuntu 16.04 does not support
multiple coprocesses, giving a warning when the second coprocess is
created ("bash: warning: execute_coproc: coproc [16388:COPROC] still
exists").

As documented in the corresponding Bash man page, the section BUGS
states that "[t]here may be only one active coprocess at a time."

Is it true that the intention of the statement in the man page is that
at most one coprocess exists for every concurrently running Bash
process where $$ expands to the same PID?

I ask the question because creating a coprocess within a coprocess
does not raise the warning.  If the answer to the question is yes,
then the warning should be raised when a coprocess is created within a
coprocess.  If the answer is no, then the man page should clarify that
the coproc within coproc case is allowed.

Thank you.

-- 
Best regards,
Eus