When I run

./pants repl

against a python library target which has

compatibility="CPython>=3.6.8,<4",

I get a py3 repl. When I run it againt a library that does not have any

compatibility

defined, I get a py2 repl. This is with

pants.ini

having a config

interpreter_constraints: ["CPython>=2.7.15,<3","CPython>=3.6.8,<4"]

When I run

./pants repl 3rdparty/python3:Flask

I get a repl dependent on what is in

.pants.d

. If I delete

.pants.d

and run with an ini file that has ``interpreter_constraints: ["CPython>=2.7.15,<3","CPython>=3.6.8,<4"]` I get a py2 repl. If I edit

pants.ini

to have

interpreter_constraints: ["CPython>=3.6.8,<4"]

I still get a py2 repl. If I delete

.pants.d

I then get a py3 repl.