Additionally, `$BASE` is set in the environment.
-g::
---gui::
+--[no-]gui::
When 'git-difftool' is invoked with the `-g` or `--gui` option
the default diff tool will be read from the configured
- `diff.guitool` variable instead of `diff.tool`.
+ `diff.guitool` variable instead of `diff.tool`. The `--no-gui`
+ option can be used to override this setting.
--[no-]trust-exit-code::
'git-difftool' invokes a diff tool individually on each file.