Haskell: webkitgtk3 library cannot be built - haskell

Question

There have been multiple tricks in the past to compile haskell libraries that are hard to find.
The webkitgtk3 library fails to build.
ERROR:
cabal install webkitgtk3
Resolving dependencies...
[1 of 2] Compiling SetupWrapper ( /tmp/webkitgtk3-0.12.5-28865/webkitgtk3-0.12.5/SetupWrapper.hs, /tmp/webkitgtk3-0.12.5-28865/webkitgtk3-0.12.5/dist/setup/SetupWrapper.o )
/tmp/webkitgtk3-0.12.5-28865/webkitgtk3-0.12.5/SetupWrapper.hs:118:28: Warning:
In the use of `configCompiler'
(imported from Distribution.Simple.Configure):
Deprecated: "'configCompiler' is deprecated. Use 'configCompilerEx' instead."
[2 of 2] Compiling Main ( /tmp/webkitgtk3-0.12.5-28865/webkitgtk3-0.12.5/Setup.hs, /tmp/webkitgtk3-0.12.5-28865/webkitgtk3-0.12.5/dist/setup/Main.o )
Linking /tmp/webkitgtk3-0.12.5-28865/webkitgtk3-0.12.5/dist/setup/setup ...
[1 of 2] Compiling Gtk2HsSetup ( Gtk2HsSetup.hs, dist/setup-wrapper/Gtk2HsSetup.o )
[2 of 2] Compiling Main ( SetupMain.hs, dist/setup-wrapper/Main.o )
Linking dist/setup-wrapper/setup ...
Configuring webkitgtk3-0.12.5...
Building webkitgtk3-0.12.5...
Preprocessing library webkitgtk3-0.12.5...
gtk2hsC2hs: Errors during expansion of binding hooks:
./Graphics/UI/Gtk/WebKit/Types.chs:1100: (column 12) [ERROR]
>>> Unknown identifier!
Cannot find a definition for `WebKitDOMBarInfo' in the header file.
./Graphics/UI/Gtk/WebKit/Types.chs:1865: (column 12) [ERROR]
>>> Unknown identifier!
Cannot find a definition for `WebKitDOMMemoryInfo' in the header file.
Failed to install webkitgtk3-0.12.5
cabal: Error: some packages failed to install:
webkitgtk3-0.12.5 failed during the building phase. The exception was:
ExitFailure 1
Any tips how to solve fix the error?

Answer 1

As mentioned in the comments, it just installed correctly for me, so I can only guess what went wrong on your machine, but the error message you gave does have some clues....
The important lines seem to be here
./Graphics/UI/Gtk/WebKit/Types.chs:1100: (column 12) [ERROR]
>>> Unknown identifier!
Cannot find a definition for `WebKitDOMBarInfo' in the header file.
./Graphics/UI/Gtk/WebKit/Types.chs:1865: (column 12) [ERROR]
>>> Unknown identifier!
Cannot find a definition for `WebKitDOMMemoryInfo' in the header file.
I downloaded the source code for webkitgtk3 by typing in "cabal unpack webkitgtk3" and cd'ing into the subdir. Looking at Graphics/UI/Gtk/WebKit/Types.chs, line 1100, I see the following
{#pointer *WebKitDOMBarInfo as BarInfo foreign newtype #} deriving (Eq,Ord)
Haskell ".chs" files are used to bind Haskell to c header files. This line is telling the compiler build tools to create a data object based on the structure found in the webkit c header file, called WebKitDOMBarInfo.
As few places to check-
Do you have the appropriate header files? On my machine, the WebKitDOMBarInfo structure is defined in a file called /usr/include/webkitgtk-3.0/webkit/WebKitDOMBarInfo.h. (the location may differ on your machine, but the file should have the same basename, WebKitDOMBarInfo.h)
If you have the file, verify that the structure is defined (actually, the struct is called _WebKitDOMBarInfo, and the version without the underscore is a typedef).
Verify that your gtk2hsC2hs is the latest version. This is the program that converts the c header files to haskell code. An older version may get confused by certain features (possibly like the typedef thing). See How to upgrade gtk2hsC2hs? to upgrade to the newest version of gtk2hsC2hs.
Verify that your system is set up properly to find the header files.
Again, because it works for me, I don't know that any of these things will solve the problem, but if you look at these things and post the results here, we can iterate again.