<story><title>My insulin pump controller has a bug</title><url>https://twitter.com/morganherlocker/status/1730455721815527429</url></story><parent_chain><item><author>mtmail</author><text>Non-twitter link: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;nitter.net&amp;#x2F;morganherlocker&amp;#x2F;status&amp;#x2F;1730455721815527429&quot; rel=&quot;nofollow noreferrer&quot;&gt;https:&amp;#x2F;&amp;#x2F;nitter.net&amp;#x2F;morganherlocker&amp;#x2F;status&amp;#x2F;173045572181552742...&lt;/a&gt; (edit: I&amp;#x27;m not the author)&lt;p&gt;&amp;quot;Notified today that my insulin pump controller has a bug where the leading decimal point will be dropped, ie: changing a dose of .21 units to 21 units. I can reproduce randomly ~1 in 5 times so probably a race condition. Easily one of the worst software bugs I have ever heard of.&amp;quot;</text></item></parent_chain><comment><author>e2le</author><text>It sounds like the bug was in the Android app. Shouldn&amp;#x27;t the microcontroller (on the pump) be validating dose values received?&lt;p&gt;(dose &amp;gt; MAX_DOSE) ? return DOSE_TOO_HIGH : return DOSE_ACCEPTED;&lt;p&gt;20 units is obviously dangerous for a single dose.</text></comment>
<story><title>My insulin pump controller has a bug</title><url>https://twitter.com/morganherlocker/status/1730455721815527429</url></story><parent_chain><item><author>mtmail</author><text>Non-twitter link: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;nitter.net&amp;#x2F;morganherlocker&amp;#x2F;status&amp;#x2F;1730455721815527429&quot; rel=&quot;nofollow noreferrer&quot;&gt;https:&amp;#x2F;&amp;#x2F;nitter.net&amp;#x2F;morganherlocker&amp;#x2F;status&amp;#x2F;173045572181552742...&lt;/a&gt; (edit: I&amp;#x27;m not the author)&lt;p&gt;&amp;quot;Notified today that my insulin pump controller has a bug where the leading decimal point will be dropped, ie: changing a dose of .21 units to 21 units. I can reproduce randomly ~1 in 5 times so probably a race condition. Easily one of the worst software bugs I have ever heard of.&amp;quot;</text></item></parent_chain><comment><author>auggierose</author><text>For software like that, not sure how anything other than formally proven correct software is acceptable. And note, no type system is gonna help you with a bug like that.</text></comment>