"Source file found twice under different module names" doesn't work in some cases

[bonprosoft]

I found that "Source file found twice under different module names" error doesn't happen in some cases.

Case1: A Path in the graph is a relative path

Files

Same as case testDuplicateModules in test-data/unit/cmdline.test (source).

.
├── mypy.ini
└── src
    ├── a.py
    ├── foo
    │   ├── bar.py
    │   └── __init__.py
    └── __init__.py

Actual behavior

$ mypy src
src/foo/bar.py: error: Source file found twice under different module names: 'src.foo.bar' and 'foo.bar'
Found 1 error in 1 file (checked 4 source files)

$ mypy `pwd`/src
src/foo/bar.py:1: error: Unsupported operand types for + ("int" and "str")
src/foo/bar.py:1: error: Unsupported operand types for + ("int" and "str")
Found 2 errors in 1 file (checked 4 source files)

Expected behavior

$ mypy src
src/foo/bar.py: error: Source file found twice under different module names: 'src.foo.bar' and 'foo.bar'
Found 1 error in 1 file (checked 4 source files)

$ mypy `pwd`/src
src/foo/bar.py: error: Source file found twice under different module names: 'src.foo.bar' and 'foo.bar'
Found 1 error in 1 file (checked 4 source files)

Case2: A Path in the graph is an absolute path

Files

Same as case testDuplicateModules in test-data/unit/cmdline.test except mypy.ini.

.
├── mypy.ini
└── src
    ├── a.py
    ├── foo
    │   ├── bar.py
    │   └── __init__.py
    └── __init__.py

• mypy.ini

[mypy]
mypy_path = /absolute/path/to/src

Actual behavior

$ mypy src
src/foo/bar.py:1: error: Unsupported operand types for + ("int" and "str")
src/foo/bar.py:1: error: Unsupported operand types for + ("int" and "str")
Found 2 errors in 1 file (checked 4 source files)

$ mypy `pwd`/src
src/foo/bar.py: error: Source file found twice under different module names: 'src.foo.bar' and 'foo.bar'
Found 1 error in 1 file (checked 4 source files)

Expected behavior

$ mypy src
src/foo/bar.py: error: Source file found twice under different module names: 'src.foo.bar' and 'foo.bar'
Found 1 error in 1 file (checked 4 source files)

$ mypy `pwd`/src
src/foo/bar.py: error: Source file found twice under different module names: 'src.foo.bar' and 'foo.bar'
Found 1 error in 1 file (checked 4 source files)

Versions

$ mypy --version
mypy 0.790+dev.8219564d365ba29dda8c4383594d9db91f26feec
$ python --version
Python 3.6.10

[JukkaL]

Once #9092 has been merged, could you please post the output when you run mypy with -v? (Feel to trim out things from the output that don't seem relevant.)

[JukkaL]

Ah I didn't notice that there's already a fix. No need do further debugging if you've already figured this out!

[bonprosoft]

I am very sorry for confusing you.
As you mentioned, I have already submitted a PR to fix the problem in #9059.