Build with cabal new-build

[andrewthad]

I just bumped some of the upper bounds, and I would like to confirm that I didn't break anything. However, attempting to build with cabal new-build gives the following error:

$ cabal new-build -w ghc-8.2.2 --constraint=transformers-compat==0.6.0.5 --constraint=http-types==0.12.1 all
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: jsaddle-webkit2gtk-0.9.4.0 (user goal)
next goal: webkit2gtk3-javascriptcore (dependency of
jsaddle-webkit2gtk-0.9.4.0)
rejecting: webkit2gtk3-javascriptcore-0.14.2.1 (conflict: requires pkg-config
package webkit2gtk-4.0>=1.1.15, not found in the pkg-config database)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: jsaddle-webkit2gtk,
webkit2gtk3-javascriptcore

[peterbecich]

This was fixed for me by installing libwebkit2gtk-4.0-dev on Debian.