e-server / gdb: thread-specific breakpoint issues about epiphany-sdk HOT 1 OPEN

$ ./gdb/gdb ./e_prime.elf -ex "set non-stop on" -ex "set target-async on" -ex "target extended-remote 192.168.0.110:51000" -ex "attach 1 &"
Reading symbols from ./e_prime.elf...done.
Remote debugging using 192.168.0.110:51000
Attaching to program: /tmp/gdb/e_prime.elf, process 1
[New Thread 1.101]
[New Thread 1.102]
[New Thread 1.103]
[New Thread 1.104]
[New Thread 1.201]
[New Thread 1.202]
[New Thread 1.203]
[New Thread 1.204]
[New Thread 1.301]
[New Thread 1.302]
[New Thread 1.303]
[New Thread 1.304]
[New Thread 1.401]
[New Thread 1.402]
[New Thread 1.403]
[New Thread 1.404]
(gdb) b sqrt thread 8
Breakpoint 1 at 0x11c
(gdb) info threads
  Id   Target Id         Frame 
* 1    Thread 1.101 (Core: 0000: halted, interruptible) (running)
  2    Thread 1.102 (Core: 0001: halted, interruptible) (running)
  3    Thread 1.103 (Core: 0002: halted, interruptible) (running)
  4    Thread 1.104 (Core: 0003: halted, interruptible) (running)
  5    Thread 1.201 (Core: 0100: halted, interruptible) (running)
  6    Thread 1.202 (Core: 0101: halted, interruptible) (running)
  7    Thread 1.203 (Core: 0102: halted, interruptible) (running)
  8    Thread 1.204 (Core: 0103: halted, interruptible) (running)
  9    Thread 1.301 (Core: 0200: halted, interruptible) (running)
  10   Thread 1.302 (Core: 0201: halted, interruptible) (running)
  11   Thread 1.303 (Core: 0202: halted, interruptible) (running)
  12   Thread 1.304 (Core: 0203: halted, interruptible) (running)
  13   Thread 1.401 (Core: 0300: halted, interruptible) (running)
  14   Thread 1.402 (Core: 0301: halted, interruptible) (running)
  15   Thread 1.403 (Core: 0302: halted, interruptible) (running)
  16   Thread 1.404 (Core: 0303: halted, interruptible) (running)
(gdb) 
Thread 8 hit Breakpoint 1, 0x0000011c in sqrt ()
interrupt -a
(gdb) 
Thread 4 stopped.
0x00000124 in sqrt ()

Thread 12 stopped.
0x0000011c in sqrt ()

Thread 11 stopped.
0x00000120 in sqrt ()

Thread 10 stopped.
0x00000120 in sqrt ()

Thread 13 stopped.
0x0000011c in sqrt ()

Thread 9 stopped.
0x0000011c in sqrt ()

Thread 7 stopped.
0x00000224 in __ieee754_sqrt ()

Thread 14 stopped.
0x00000224 in __ieee754_sqrt ()

Thread 6 stopped.
0x00000122 in sqrt ()

Thread 5 stopped.
0x0000011c in sqrt ()

Thread 15 stopped.
0x0000011c in sqrt ()

Thread 3 stopped.
0x00000124 in sqrt ()

Thread 2 stopped.
0x0000011c in sqrt ()

Thread 16 stopped.
0x0000011c in sqrt ()

Thread 1 stopped.
0x00000120 in sqrt ()
c -a &
Continuing.
(gdb) info threads
  Id   Target Id         Frame 
* 1    Thread 1.101 (Core: 0000: halted, interruptible) (running)
  2    Thread 1.102 (Core: 0001: halted, interruptible) (running)
  3    Thread 1.103 (Core: 0002: halted, interruptible) (running)
  4    Thread 1.104 (Core: 0003: halted, interruptible) (running)
  5    Thread 1.201 (Core: 0100: halted, interruptible) (running)
  6    Thread 1.202 (Core: 0101: halted, interruptible) (running)
  7    Thread 1.203 (Core: 0102: halted, interruptible) (running)
  8    Thread 1.204 (Core: 0103: halted, interruptible) (running)
  9    Thread 1.301 (Core: 0200: halted, interruptible) (running)
  10   Thread 1.302 (Core: 0201: halted, interruptible) (running)
  11   Thread 1.303 (Core: 0202: halted, interruptible) (running)
  12   Thread 1.304 (Core: 0203: halted, interruptible) (running)
  13   Thread 1.401 (Core: 0300: halted, interruptible) (running)
  14   Thread 1.402 (Core: 0301: halted, interruptible) (running)
  15   Thread 1.403 (Core: 0302: halted, interruptible) (running)
  16   Thread 1.404 (Core: 0303: halted, interruptible) (running)
(gdb) 
Thread 8 hit Breakpoint 1, 0x0000011c in sqrt ()
c -a &
Continuing.
[this interrupt issued immediately after continue ]
(gdb) interrupt -a
(gdb) 
Thread 14 stopped.
0x0000024e in __ieee754_sqrt ()

Thread 13 stopped.
0x0000023c in __ieee754_sqrt ()
/home/esim/esdk-submodule/gdb/gdb/infrun.c:2402: internal-error: void resume(gdb_signal): Assertion `!tp->stop_requested' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)