1! RUN: %S/test_errors.sh %s %t %f18
2module m
3  interface
4    module subroutine s()
5    end subroutine
6  end interface
7end
8
9submodule(m) s1
10end
11
12submodule(m) s2
13end
14
15submodule(m:s1) s3
16  integer x
17end
18
19!ERROR: Module 'm' already has a submodule named 's3'
20submodule(m:s2) s3
21  integer y
22end
23