Cannot process directories having names with dots

[SimoneMSR]

When trying to minify files within a directory whose name has dots, the error EISDIR occurs.

GruntFile I used is

module.exports = function(grunt) {
//configuration
grunt.initConfig({
      uglify: {
          all: {
            files: [{
                expand: true,
                src: ['**/*.js',"!build/**/*"],
                dest: 'build/',
                cwd: './',
            }]
           }
         }
})
    grunt.loadNpmTasks('grunt-contrib-uglify');
   //Register Tasks
   grunt.registerTask('default', ['uglify']);
}

Version used: 5.2.2
Grunt version: 1.6.1