[Java] The story that the build error did not stop when using Eclipse 2020

1 minute read

The other day, when I was developing a Java Spring team, two team members including myself got the same error and became almost inoperable.
I do not know the root cause, but from the conclusion it seems that it was a phenomenon that occurs only in the latest version of eclipse.


  • IDE
    • Eclipse 2020-6
    • SpringToolSuite4(Eclipse4.16)
  • Java
    • 11
  • Framework
    • Spring Boot
  • OS
    –Occurs on both Windows / Mac


If an automatic build is performed in a situation where a compile error such as a reference to an object outside the scope or a reference error of a static member occurs, the build error will be repeated as shown below.
It doesn’t stop until you restart Eclipse or remove Java builder from project properties → builder [^ 1].
[^ 1]: This makes the IDE just a notepad.
スクリーンショット 2020-07-07 17.13.52.png

For error details
‘Errors running builder’Java Builder’ on project’ Somehow project’. Java.lang.NullPointerException’
In other words, “a nullpo occurred while the Java builder was running.”

Actions tried

–Git clone again after permanently removing the project from the workspace
–Change JDK version
–Rebuild & reinstall dependencies

All were useless.


Dropped Eclipse version to 2019_12.

It’s just this, but the build error no longer appears even though it is the exact same project.
Both members are in the same situation, so I think it’s probably an IDE bug.
I couldn’t find an article that solved a similar error, so I’ll share it.