caplog fails on getting caplog.messages with str.format() log record

[gurobokum]

Description

In dvc we can use logger.info as

logger.info("{} in str.format()", "log")

because of the custom formatter
but caplog uses default LogRecord.getMessage()

if self.args:
      msg = msg % self.args 

and fails in tests on getting caplog.messages

Steps to reproduce

Create a file with content

def test_caplog(caplog):
    import logging
    logger = logging.getLogger()

    with caplog.at_level(logging.INFO):
        logger.info("This shouldn't fail {}", 1)

    assert len(caplog.messages) == 1

Run it

pytest test_caplog

Produces an error like

test_caplog.py:8:                                                                                                                                      
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
../../../.pyenv/versions/3.7.6/envs/dvc/lib/python3.7/site-packages/_pytest/logging.py:387: in messages                                                
    return [r.getMessage() for r in self.records]                                                                                                      
../../../.pyenv/versions/3.7.6/envs/dvc/lib/python3.7/site-packages/_pytest/logging.py:387: in <listcomp>                                              
    return [r.getMessage() for r in self.records]   
....
>           msg = msg % self.args                                                                                           
E           TypeError: not all arguments converted during string formatting                                                 
                                                                                                                           
../../../.pyenv/versions/3.7.6/lib/python3.7/logging/__init__.py:369: TypeError

Info

$ dvc --version
0.86.2+002dd8.mod

[efiop]

Most likely related to our handler using a special non-default format for lazy logging. Need to switch to the default one, to be compatible with default handlers.

[skshetry]

Need to switch to the default one, to be compatible with default handlers.

You mean, to move to percent-formatted strings?

[efiop]

@skshetry Yeah, probably would do that to avoid messing around with different loggers. Could use their version of {} too though.