Resolving dependencies...
cabal: Could not resolve dependencies:
[__0] trying: monomer-1.0.0.0 (user goal)
[__1] next goal: sdl2 (dependency of monomer)
[__1] rejecting: sdl2-2.5.3.0, sdl2-2.5.2.0, sdl2-2.5.1.0, sdl2-2.5.0.0
(conflict: pkg-config package sdl2==2.0.6 || >2.0.6, not found in the
pkg-config database)
[__1] rejecting: sdl2-2.4.1.0, sdl2-2.4.0.1, sdl2-2.4.0 (conflict: pkg-config
package sdl2==2.0.4 || >2.0.4, not found in the pkg-config database)
[__1] rejecting: sdl2-2.3.0 (conflict: monomer => sdl2>=2.4.0 && <2.6)
[__1] skipping: sdl2-2.2.0, sdl2-2.1.3.1, sdl2-2.1.3, sdl2-2.1.2.1,
sdl2-2.1.2, sdl2-2.1.1, sdl2-2.1.0, sdl2-2.0.0, sdl2-1.3.1, sdl2-1.3.0,
sdl2-1.2.0, sdl2-1.1.3, sdl2-1.1.2, sdl2-1.1.1, sdl2-1.1.0, sdl2-1.0.2,
sdl2-1.0.1, sdl2-1.0.0, sdl2-2.3.0.1 (has the same characteristics that caused
the previous version to fail: excluded by constraint '>=2.4.0 && <2.6' from
'monomer')
[__1] fail (backjumping, conflict set: monomer, sdl2)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: sdl2, monomer