Cabal install error with conflicting constraints

Question

So right now I'm trying to run cabal install --lib bytestring, seems simple enough. But every time I run this I get this error message:

Resolving dependencies...
cabal: Could not resolve dependencies:
[__0] next goal: bytestring (user goal)
[__0] rejecting: bytestring-0.11.3.1, bytestring-0.11.3.0,
bytestring-0.11.2.0, bytestring-0.11.1.0, bytestring-0.11.0.0,
bytestring-0.10.12.1 (constraint from user target requires ==0.10.12.0)
[__0] rejecting: bytestring-0.10.12.0/installed-0.10.12.0,
bytestring-0.10.12.0 (constraint from user target requires ==0.11.3.1)
[__0] rejecting: bytestring-0.10.10.1, bytestring-0.10.10.0,
bytestring-0.10.9.0, bytestring-0.10.8.2, bytestring-0.10.8.1,
bytestring-0.10.8.0, bytestring-0.10.6.0, bytestring-0.10.4.1,
bytestring-0.10.4.0, bytestring-0.10.2.0, bytestring-0.10.0.2,
bytestring-0.10.0.1, bytestring-0.10.0.0, bytestring-0.9.2.1,
bytestring-0.9.2.0, bytestring-0.9.1.10, bytestring-0.9.1.9,
bytestring-0.9.1.8, bytestring-0.9.1.7, bytestring-0.9.1.6,
bytestring-0.9.1.5, bytestring-0.9.1.4, bytestring-0.9.1.3,
bytestring-0.9.1.2, bytestring-0.9.1.1, bytestring-0.9.1.0,
bytestring-0.9.0.4, bytestring-0.9.0.3, bytestring-0.9.0.2,
bytestring-0.9.0.1, bytestring-0.9 (constraint from user target requires
==0.10.12.0)
[__0] fail (backjumping, conflict set: bytestring)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: bytestring

It appears that cabal has conflicting constraints that prevent it from installing 0.10.12.0 or 0.11.3.1 (fyi: i'm trying to use 0.10.12.0). How can I remove the "version==0.11.3.1" constraint? ty.