Green’s Dictionary of Slang

sugar adj.

easy, comfortable.

[UK]J. Greenwood Seven Curses of London 90: ‘Anybody, to hear ’em talk,’ a thief once remarked to me [...], ‘anybody would think, to hear ’em talk, that it was all sugar with us while we were free, and that our sufferings did not begin until we were caught, and ‘put away.’.
[Aus]D.V. Lucas Aus. and Homeward 335: [as cit. 1869].