Failed to install erd with cabal.
$ cabal install erd
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: erd-0.1.3.0 (user goal)
next goal: base (dependency of erd-0.1.3.0)
rejecting: base-4.9.1.0/installed-4.9... (conflict: erd => base==4.7.*)
rejecting: base-4.9.1.0, base-4.9.0.0, base-4.8.2.0, base-4.8.1.0,
base-4.8.0.0, base-4.7.0.2, base-4.7.0.1, base-4.7.0.0, base-4.6.0.1,
base-4.6.0.0, base-4.5.1.0, base-4.5.0.0, base-4.4.1.0, base-4.4.0.0,
base-4.3.1.0, base-4.3.0.0, base-4.2.0.2, base-4.2.0.1, base-4.2.0.0,
base-4.1.0.0, base-4.0.0.0, base-3.0.3.2, base-3.0.3.1 (constraint from
non-upgradeable package requires installed instance)
Dependency tree exhaustively searched.
$
FYI, my environment is follows.
sw_vers
ProductName: Mac OS X
ProductVersion: 10.12.4
BuildVersion: 16E195
Failed to install erd with cabal.
FYI, my environment is follows.