SourceMap referes to wrong files and lines

[dawidk92]

Im generating SourceMap by grunt-sass (1.0.0) and Im including foundation (5.5.2) into it

sass: {
    options: {
        includePaths: [
            'bower_components/foundation/scss'
        ],
        sourceMap: true
    },
    dist: {
        files: { '<%= dir.css %>/main.css': '<%= dir.sass %>/app.scss' }
    }
}

It works fine but when Im using cssmin (0.12.3) SourceMap breaks and doesnt work properly anymore

cssmin: {
    combine: {
        options: {
            keepSpecialComments: 0,
            sourceMap: true
        },
        files: {
            '<%= dir.css %>/main.css': ['<%= dir.css %>/main.css']
        }
    }
}

[XhmikosR]

Duplicate of #204 #248