Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: music-sibelius (user goal)
rejecting: music-sibelius-1.9.0, music-sibelius-1.8.1, music-sibelius-1.8,
music-sibelius-1.7.2, music-sibelius-1.7.1, music-sibelius-1.7,
music-sibelius-1.6.2, music-sibelius-1.6.1 (constraint from user target
requires ==1.6)
trying: music-sibelius-1.6
trying: lens-4.15.1 (dependency of music-preludes-1.6)
next goal: music-score (dependency of music-sibelius-1.6)
rejecting: music-score-1.9.0, music-score-1.8.1, music-score-1.8,
music-score-1.7.2, music-score-1.7.1, music-score-1.7, music-score-1.6.2,
music-score-1.6.1 (conflict: music-sibelius => music-score==1.6)
rejecting: music-score-1.6 (conflict: lens==4.15.1, music-score => lens>=4.0
&& <4.1)
rejecting: music-score-1.3.1, music-score-1.3, music-score-1.2.2,
music-score-1.2.1, music-score-1.2 (conflict: music-sibelius =>
music-score==1.6)
Backjump limit reached (currently 2000, change with --max-backjumps or try to
run with --reorder-goals).