Warning: The install command is a part of the legacy v1 style of cabal usage.

Please switch to using either the new project style and the new-install
command or the legacy v1-install alias as new-style projects will become the
default in the next version of cabal-install. Please file a bug if you cannot
replicate a working v1- use case with the new-style commands.

For more information, see: https://wiki.haskell.org/Cabal/NewBuild

Resolving dependencies...
cabal: Could not resolve dependencies:
[__0] trying: patch-image-0.3.3.1 (user goal)
[__1] trying: patch-image:+llvm
[__2] next goal: fft (dependency of patch-image +llvm)
[__2] rejecting: fft-0.1.8.6, fft-0.1.8.5, fft-0.1.8.4, fft-0.1.8.3,
fft-0.1.8.2, fft-0.1.8.1, fft-0.1.8, fft-0.1.7.3, fft-0.1.7.2, fft-0.1.7.1,
fft-0.1.7 (conflict: pkg-config package fftw3>=3.3 && <4, not found in the
pkg-config database)
[__2] rejecting: fft-0.1.6, fft-0.1.5, fft-0.1.4, fft-0.1.3, fft-0.1.2,
fft-0.1.1, fft-0.1.0.1, fft-0.1.0.0 (conflict: patch-image +llvm => fft>=0.1.7
&& <0.2)
[__2] fail (backjumping, conflict set: fft, patch-image, patch-image:llvm)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: fft, patch-image, patch-image:llvm