https://devzone.nordicsemi.com/f/nordic-q-a/35328/undefined-symble-error-about-stdlib-in-nrf5-sdk-keil-projectHi everyone, I&#39;m in trouble with the stdlib of Keil SDK , which is nRF5_SDK_15.0.0_a53641a, while compliing. The code what I add in the demo project causes Undefined symble error reported as above. However, I notice that exit() and system() areen-USTelligent Community 13Thu, 14 Jun 2018 13:07:53 GMThttps://devzone.nordicsemi.com/thread/136185?ContentTypeID=1Thu, 14 Jun 2018 13:07:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5d95101c-99a2-437b-aa91-3ff534463bd5piepie<p>thanks, bro. It&#39;s ok now.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/136042?ContentTypeID=1Thu, 14 Jun 2018 06:42:50 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5b123037-d9b0-4b39-8c0a-92f06ec0defcVidar Berg<p>Do you require RTT for logging, or can you use UART instead? You will not&nbsp;get these errors if you remove the RTT files in your project.&nbsp;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/135959?ContentTypeID=1Wed, 13 Jun 2018 13:50:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8646f58b-59b8-4ebc-8e36-13bd400e36a2piepie<p>Hi Vidar, I tried. Other error occours as follows.</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1528897768860v1.png" alt=" " /></p> <p>Some advice?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/135854?ContentTypeID=1Wed, 13 Jun 2018 08:41:15 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f318047f-f1a9-4ef7-bd81-35896c8bb833Vidar Berg<p>Hi,</p> <p>Did you try&nbsp;building without<strong> <a href="http://www.keil.com/arm/microlib.asp">MicroLIB</a>&nbsp;</strong>enabled?&nbsp;&nbsp;<strong>stdlib</strong>&nbsp;is a part of the ARM/Keil toolchain.</p><div style="clear:both;"></div>