Steps to produce bug :
1.mvn hpi:run
2.Set access keys ,
Then it throws following exception -
2013-01-25 18:29:38.039::WARN: /descriptorByName/hudson.plugins.ec2.AmazonEC2Cloud/fillRegionItems
java.lang.IllegalStateException: Connection not obtained from this manager
at org.apache.http.util.Asserts.check(Asserts.java:34)
at org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager.releaseConnection(ThreadSafeClientConnManager.java:252)
at org.apache.http.impl.conn.AbstractClientConnAdapter.abortConnection(AbstractClientConnAdapter.java:338)
at org.apache.http.impl.client.DefaultRequestDirector.abortConnection(DefaultRequestDirector.java:1119)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:590)
at org.apache.http.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:858)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:76)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:97)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:58)
at com.amazonaws.http.AmazonHttpClient.executeHelper(AmazonHttpClient.java:262)
at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:169)
at com.amazonaws.services.ec2.AmazonEC2Client.invoke(AmazonEC2Client.java:5684)
at com.amazonaws.services.ec2.AmazonEC2Client.describeRegions(AmazonEC2Client.java:768)
at com.amazonaws.services.ec2.AmazonEC2Client.describeRegions(AmazonEC2Client.java:4534)
at hudson.plugins.ec2.AmazonEC2Cloud$DescriptorImpl.doFillRegionItems(AmazonEC2Cloud.java:96)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:282)
at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:149)
at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:88)
at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:104)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:561)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:646)
at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:234)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:561)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:646)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:477)
at org.kohsuke.stapler.Stapler.service(Stapler.java:159)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:491)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1074)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:94)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:86)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:47)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at org.mortbay.jetty.servlet.ServletHandler.hand

And Regions wont be populated