Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: eigen (user goal)
rejecting: eigen-2.1.6, eigen-2.0.1, eigen-2.0.0, eigen-1.2.5, eigen-1.2.4,
eigen-1.2.2, eigen-1.2.1, eigen-1.1.2, eigen-2.1.5, eigen-2.1.4, eigen-2.1.3,
eigen-2.1.2, eigen-2.1.1 (constraint from user target requires ==2.1.0)
trying: eigen-2.1.0
trying: base-4.9.0.0/installed-4.9... (dependency of eigen-2.1.0)
next goal: primitive (dependency of eigen-2.1.0)
rejecting: primitive-0.6.2.0, primitive-0.6.1.0 (conflict: eigen =>
primitive>=0.1 && <0.6)
rejecting: primitive-0.5.4.0 (conflict: base==4.9.0.0/installed-4.9...,
primitive => base>=4.3 && <4.9)
rejecting: primitive-0.5.3.0, primitive-0.5.2.1 (conflict:
base==4.9.0.0/installed-4.9..., primitive => base>=4.3 && <4.8)
rejecting: primitive-0.5.1.0 (conflict: base==4.9.0.0/installed-4.9...,
primitive => base>=4 && <4.8)
rejecting: primitive-0.5.0.1, primitive-0.5, primitive-0.4.1,
primitive-0.4.0.1, primitive-0.4, primitive-0.3.1, primitive-0.3 (conflict:
base==4.9.0.0/installed-4.9..., primitive => base>=4 && <4.7)
rejecting: primitive-0.2.1, primitive-0.2, primitive-0.1 (conflict:
base==4.9.0.0/installed-4.9..., primitive => base>=2 && <4.7)
rejecting: primitive-0.6 (conflict: eigen => primitive>=0.1 && <0.6)
Dependency tree exhaustively searched.