Can't build gtk3-0.13.6 with ghc-7.10.1

[AphonicChaos]

I'm unable to get gtk3 to build. I successfully installed build tools an other dependencies. Something seems to parse incorrectly in comments. Once I remove the comments (obviously not a solution), build seems to progress further, though it continues to fail on errors similar to the one I documented below.

cabal install ./gtk                                     
Resolving dependencies...
Configuring gtk3-0.13.6...
Building gtk3-0.13.6...
Failed to install gtk3-0.13.6
Build log ( /home/edwin/.cabal/logs/gtk3-0.13.6.log ):
[1 of 2] Compiling SetupWrapper     ( gtk/SetupWrapper.hs, gtk/dist/setup/SetupWrapper.o )
[2 of 2] Compiling Main             ( gtk/dist/setup/setup.hs, gtk/dist/setup/Main.o )
Linking ./gtk/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 gtk3-0.13.6...
Building gtk3-0.13.6...
Preprocessing library gtk3-0.13.6...

Graphics/UI/Gtk/Display/Statusbar.chs:40:10:
    parse error on input ‘bars’
cabal: Error: some packages failed to install:
gtk3-0.13.6 failed during the building phase. The exception was:

My system:

$ cabal --version
cabal-install version 1.22.2.0
using version 1.22.2.0 of the Cabal library 

$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 7.10.1

$ uname -a
Linux arch-mage 4.0.1-1-ARCH #1 SMP PREEMPT Wed Apr 29 12:00:26 CEST 2015 x86_64 GNU/Linux

I've tried with the git version (latest commit: 9e9a8f1) and whats currently on hackage (0.13.6)

[markwright]

It builds fine on Gentoo with gcc 4.9.2, and fails with gcc 5.1.0 due to the change noted in the "Preprocessor issues" section of
https://gcc.gnu.org/gcc-5/porting_to.html
Which I workaround with:

sed -e 's@gccProg, "--cppopts=-E"@gccProg, "--cppopts=-E", "--cppopts=-P"@' -i Gtk2HsSetup.hs

[AphonicChaos]

Just confirmed @markwright's work-around solves my problem. Thanks!