-e <pattern>, --exclude=<pattern>
    In addition to those found in .gitignore (per directory) and
    $GIT_DIR/info/exclude, also consider these patterns to be in
    the set of the ignore rules in effect.

-x
    Don’t use the standard ignore rules read from .gitignore
    (per directory) and $GIT_DIR/info/exclude, but do still use
    the ignore rules given with -e options. This allows removing
    all untracked files, including build products. This can be
    used (possibly in conjunction with git reset) to create a
    pristine working directory to test a clean build.

-X
    Remove only files ignored by Git. This may be useful to
    rebuild everything from scratch, but keep manually created
    files.