Running mypy on .py file with known problems in Cygwin term produces no output. Running same command on same file in DOS window produces expected output.

Brendan Keefe
Sun Feb 6 20:04:50 GMT 2022

I have attached cygcheck.out.  Following are some details, to
elaborate upon the subject line.

Contents of the file

# begin code listing

def greeting(name: str) -> str:
    return 'Hello ' + name

if __name__ == "__main__":
    greeting('Bob', 'Eve')

# end code listing

Output when running in a DOS (cmd) window is what I expected:

C:\bjk\tmp>mypy error: Too many arguments for "greeting" error: Argument 1 to "greeting" has incompatible type
"int"; expected "str" error: Argument 1 to "greeting" has incompatible type
"bytes"; expected "str"
Found 3 errors in 1 file (checked 1 source file)

When I run the same command on the same file in a Cygwin terminal
window, there is no output. (Same lack of results if I use the -v or
--strict flags.) There is a noticeable span of time (~0.5 sec) before
the next command prompt appears, so it seems to me like something is
being run in response to the command.

On a probably related note, running in DOS window causes creation of a
directory named .mypy_cache. No such directory is created when running
in a Cygwin terminal.

Anyone got any ideas? Thanks in advance.

P.S. Running on Win10, Python 3.9.6 as downloaded from (for
Windows). Version of mypy: 0.931, obtained via python -m pip install
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