Metadata-generation-failed

[MepHist2721Y]

Why this error... Please help.

Collecting mailer Using cached mailer-0.8.1.zip (6.5 kB) Preparing metadata (setup.py) ... error error: subprocess-exited-with-error

× python setup.py egg_info did not run successfully. │ exit code: 1 ╰─> [1 lines of output] error in mailer setup command: use_2to3 is invalid. [end of output]

note: This error originates from a subprocess, and is likely not a problem with pip. error: metadata-generation-failed

× Encountered error while generating package metadata. ╰─> See above for output.

note: This is an issue with the package mentioned above, not pip. hint: See above for details.