How to compile sass / scss without creating map files

Answer:

Add --sourcemap=none to your command.

So it will look like:

sass --watch scss:css --style compressed --sourcemap=none

Update for 2019

Running --sourcemap-none on the latest version of sass (1.21.0) returns Could not find an option named "sourcemap".

The new flag is --no-source-map.

━━━ Source Maps ━━━━━━━━━━━━━━━━━━━━━━━━
--[no-]source-map          Whether to generate source maps.
                           (defaults to on)

--source-map-urls          How to link from source maps to source files.
                           [relative (default), absolute]

--[no-]embed-sources       Embed source file contents in source maps.
--[no-]embed-source-map    Embed source map contents in CSS.

Also, sass is one of the many CLI programs with built-in help output. Running sass without any arguments shows usage instruction and various flags, like this one.

Update, now the proper command to avoid creating a map file is:

--no-source-map