A few issues inspired by the coproc proposal in this thread:
http://lists.gnu.org/archive/html/bug-bash/2016-04/msg00050.html
1. coproc unsets readonly NAME after the process completes
$ declare -p UID; coproc UID { :; }; wait; declare -p UID
declare -ir UID="501"
bash: UID: readonly variable
bash: UID: readonly variable
[1] 60652
[1]+ Done coproc UID { :; }
bash: declare: UID: not found
2. Segfault if NAME is an existing associative array
$ declare -A A; coproc A { :; }
0 bash 0x0000000100e61075 hash_search + 53
(hashlib.c:141)
1 bash 0x0000000100e6bf74 assoc_insert + 36
(assoc.c:77)
2 bash 0x0000000100e6a8a7
bind_array_var_internal + 87 (arrayfunc.c:183)
3 bash 0x0000000100e34619 coproc_setvars + 121
(execute_cmd.c:2173)
4 bash 0x0000000100e2fb52
execute_command_internal + 738 (execute_cmd.c:2281)
5 bash 0x0000000100e30e07
execute_command_internal + 5527 (execute_cmd.c:2562)
6 bash 0x0000000100e2f809 execute_command + 137
(execute_cmd.c:405)
7 bash 0x0000000100e1c986 reader_loop + 662
(eval.c:180)
8 bash 0x0000000100e1bc15 main + 6709
(shell.c:610)
3. If NAME is $,?,@, etc, bash will create a new array variable with that
name. This zeroth index of this array variable will then take precedence
over the real variable in some contexts
$ echo ${@:0}; coproc @ { sleep 1; }; echo ${@:0}
-bash
[1] 72037
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