Magit runs Git either for side-effects (e.g. when pushing) or to get some value (e.g. the name of the current branch).
When Git is run for side-effects, the process output is logged in a
per-repository log buffer, which can be consulted using the
magit-process command when things don’t go as expected.
The output/errors for up to ‘magit-process-log-max’ Git commands are retained.
This commands displays the process buffer for the current repository.
Inside that buffer, the usual key bindings for navigating and showing sections are available. There is one additional command.
This command kills the process represented by the section at point.
When this is non-nil then the output of all calls to git are logged in the process buffer. This is useful when debugging, otherwise it just negatively affects performance.