$ javac broken/NoSuchModule.java     (25.0.4.1+1-LTS)
broken/NoSuchModule.java:1: error: imported module not found: java.nosuch
import module java.nosuch;
^
1 error

$ javac broken/NoSuchModule.java     (27+35)
broken/NoSuchModule.java:1: error: imported module not found: java.nosuch
import module java.nosuch;
^
1 error

$ javac broken/ModuleInsideClass.java     (25.0.4.1+1-LTS)
broken/ModuleInsideClass.java:2: error: illegal start of type
    import module java.base;
    ^
broken/ModuleInsideClass.java:2: error: ';' expected
    import module java.base;
                      ^
broken/ModuleInsideClass.java:2: error: <identifier> expected
    import module java.base;
                           ^
3 errors

$ javac broken/ModuleInsideClass.java     (27+35)
broken/ModuleInsideClass.java:2: error: illegal start of type
    import module java.base;
    ^
broken/ModuleInsideClass.java:2: error: ';' expected
    import module java.base;
                      ^
broken/ModuleInsideClass.java:2: error: <identifier> expected
    import module java.base;
                           ^
3 errors

$ javac --release 21 src/NewWay.java     (25.0.4.1+1-LTS)
src/NewWay.java:1: error: module imports are not supported in -source 21
import module java.base;
       ^
  (use -source 25 or higher to enable module imports)
1 error
exit=1

$ javac --release 24 src/NewWay.java     (25.0.4.1+1-LTS)
src/NewWay.java:1: error: module imports are not supported in -source 24
import module java.base;
       ^
  (use -source 25 or higher to enable module imports)
1 error
exit=1

$ javac --release 25 src/NewWay.java     (25.0.4.1+1-LTS)
exit=0

$ javac src/NewWay.java     (21.0.10+7-Ubuntu-124.04)
src/NewWay.java:1: error: '.' expected
import module java.base;
             ^
1 error