Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: btree-concurrent (user goal)
rejecting: btree-concurrent-0.1.5, 0.1.4 (global constraint requires ==0.1.3)
trying: btree-concurrent-0.1.3
trying: bytestring-0.10.4.0/installed-9f4... (dependency of
btree-concurrent-0.1.3)
next goal: deepseq (dependency of bytestring-0.10.4.0/installed-9f4...)
rejecting: deepseq-1.3.0.2/installed-733... (conflict: deepseq =>
array==0.5.0.0/installed-98a..., btree-concurrent => array==0.4.*)
rejecting: deepseq-1.4.1.1, 1.4.1.0, 1.4.0.0, 1.3.0.2, 1.3.0.1, 1.3.0.0,
1.2.0.1, 1.2.0.0, 1.1.0.2, 1.1.0.1, 1.1.0.0, 1.0.0.0 (conflict: bytestring =>
deepseq==1.3.0.2/installed-733...)
Dependency tree exhaustively searched.