pre-commit

#!/bin/sh

if git rev-parse --verify HEAD >/dev/null 2>&1; then
    against=HEAD
else
    against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi

function clean_up {
    git stash pop -q
    return
}

git stash -q --keep-index

for FILE in `git diff-index --name-status $against -- | sed '/^D/ d' | cut -c3-` ; do
    # Check if the file contains 'debugger'
    if grep --quiet debugger "$FILE"; then
        echo '\033[31mCOMMIT ABORTED -' $FILE 'contains a debugger statement.'
        clean_up
        exit 1
    fi

    if grep --quiet "^[><=]\{7\}" "$FILE"; then
        echo '\033[31mCOMMIT ABORTED -' $FILE 'appears to have an unresolved merge.'
        clean_up
        exit 1
    fi

    if [[ $FILE =~ .*(BACKUP)|(BASE)|(LOCAL)|(REMOTE).* ]]; then
        echo '\033[31mCOMMIT ABORTED -' $FILE 'is a temporary merge file.'
        clean_up
        exit 1
    fi
done

clean_up
exit

This will prevent a commit if the file contains debugger

Tested to work on OS X.

Added the sed bit to make it ignore deletes. Go ahead and delete a file with a debugger in it!