error: Untracked working tree file

$ git pull --rebase
First, rewinding head to replay your work on top of it...
error: Untracked working tree file 'Utilities/gdcm/Utilities/gdcmjpeg/Jfif.txt' would be overwritten by merge.
could not detach HEAD


git reset --hard
git reset --hard ORIG_HEAD
git reset --soft HEAD^
git reset --hard
git checkout -f master
git clean -n -d
git clean -d Utilities/gdcm/Source/InformationObjectDefinition/Part3.xml
git clean -f -d Utilities/gdcm/Source/InformationObjectDefinition/Part3.xml
git clean -f -d Utilities/gdcm/Source/MediaStorageAndFileFormat/TODO.txt
git clean -f -d Utilities/gdcm/TODO
git clean -f -d Utilities/gdcm/Utilities/gdcmjpeg/Jfif.txt
git clean -f -d Utilities/gdcm/Utilities/gdcmjpeg/install.doc
git clean -f -d Utilities/gdcm/Utilities/gdcmjpeg/libjpeg.doc
git clean -f -d Utilities/gdcm/Utilities/gdcmjpeg/usage.doc
git rebase --skip