Unsupported class file major version 65 when building Iceberg 1.4.x with JDK 1.8

[JackeeH]

Apache Iceberg version

1.4.3

Query engine

None

Please describe the bug 🐞

I am using OpenJDK 1.8 and trying to build Iceberg 1.4.x using the command ./gradlew build -x test -x integrationTest. However, I encountered a failure while building the subproject Task :iceberg-spark:iceberg-spark-runtime-3.5_2.12:shadowJar, which is likely related to shadow plugin.
During the build process, it can be confirmed that I am using JDK1.8.
The error message is as follows.

Willingness to contribute

• I can contribute a fix for this bug independently
• I would be willing to contribute a fix for this bug with guidance from the Iceberg community
• I cannot contribute a fix for this bug at this time

[JackeeH]

The stack picture is not very clear, you can see the picture below:

[nastra]

I do recall that this was potentially an issue with the Shadow plugin we were using at the time when 1.4.x was released (GradleUp/shadow#894). We're not going to do another 1.4.x release with the fix but I've attached the below patch as a workaround for people that want to build Iceberg 1.4.x with JDK8: jdk8.patch

@JackeeH can you confirm that the attached patch works for you?

[JackeeH]

@nastra Yes, I can confirm that I did successfully build version 1.4.x by using the command ./gradlew build -x test -x integrationTest after applying this patch.

[nastra]

thanks for confirming @JackeeH. I'll close this then since we have a documented workaround for this