The build will succeed but it is possible that the artifacts that you built won't actually work if run with JRE 7 for a few reasons (for example you may have linked against a method that was added in a later version of the JRE). This isn't a problem for a normal user because they typically are not shipping the Apache Beam artifacts.
When cross compiling[1], you really need to set -source, -target, -bootclasspath and -extdirs to get rid of this warning. Its very difficult to actually set the -bootclasspath and -extdirs in a general Maven project because we need to know that the user has the JDK of the specific version installed. This is why we don't force it on users but instead have a post commit test[2] that validates that the Java 7 modules build with JDK 7. [1]: https://github.com/apache/beam/blob/f9bc76364636b92239510f9e6bd242ea0ea62ac6/.test-infra/jenkins/job_beam_PostCommit_Java_JDKVersionsTest.groovy [2]: http://docs.oracle.com/javase/7/docs/technotes/tools/windows/javac.html On Tue, Oct 3, 2017 at 10:47 AM, Ryan Niemocienski <ni...@google.com.invalid > wrote: > Hey Beam, > > I'm attempting to patch beam (PR here: > https://github.com/apache/beam/pull/3933) but am running into a warning > that I can't figure out the cause to. The warning is "bootstrap class path > not set in conjunction with -source 1.7" which, after some googling, seems > like it's an issue with building sources to target one java version while > using backwards incompatible features? I might be misunderstanding though. > Weirdly, "mvn clean verify" succeeds locally. > > Posting here to see if anyone's run into this, or knows of a possible > solution. > > Full build context here: > https://builds.apache.org/job/beam_PreCommit_Java_ > MavenInstall/14761/org.apache.beam$beam-sdks-java-io-google- > cloud-platform/console >