VS2015+VisualGDB在OpenOCD下连接不了ST-Link的原因？

想用VS2015+VisualGDB来代替Keill，安装后OpenOCD不能与St-Link连接，无法下载程序。。
错误信息如下：
C:UsersRnAppDataLocalVisualGDBEmbeddedDebugPackagescom.sysprogs.arm.openocdbinopenocd.exe -f interface/stlink-v2.cfg -c "transport select hla_swd" -f target/STM32f0x.cfg -c init -c "reset init" -c "gdb_port 53035" -c "telnet_port 53034"  
Open On-Chip Debugger 0.10.0 (2017-06-09) [http://github.com/sysprogs/openocd]
Licensed under GNU GPL v2
For bug reports, read
        http://openocd.org/doc/doxygen/bugs.html
hla_swd
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
adapter speed: 1000 kHz
adapter_nsrst_delay: 100
none separate
Info : Unable to match requested speed 1000 kHz, using 950 kHz
Info : Unable to match requested speed 1000 kHz, using 950 kHz
Info : clock speed 950 kHz
Info : STLINK v2 JTAG v28 API v2 SWIM v7 VID 0x0483 PID 0x3748
Info : using stlink api v2
Info : Target voltage: 0.086228
Error: target voltage may be too low for reliable debugging
Error: init mode failed (unable to connect to the target)
in procedure 'init'
in procedure 'ocd_bouncer'