don't run cabal haddock for meta libraries

ghc-rpm-macros.spec

@@ -101,6 +101,7 @@ EOF
 * Sat Jan 31 2015 Jens Petersen <petersen@redhat.com> - 1.4.6-1
 - disable Cabal tests on armv7 since they give an internal error
   https://ghc.haskell.org/trac/ghc/ticket/10029
+- only run cabal haddock for real libraries with modules
 
 * Sat Jan 31 2015 Jens Petersen <petersen@redhat.com> - 1.4.5-1
 - fix the R*PATH regexp

macros.ghc

@@ -106,7 +106,11 @@ install -D --mode=0644 %{pkgnamever}.conf %{buildroot}%{ghclibdir}/package.conf.
 %ghc_lib_build()\
 %ghc_lib_build_without_haddock\
 %if %{undefined without_haddock}\
+%define pkgname %{?1}%{!?1:%{pkg_name}}\
+%define pkgver %{?2}%{!?2:%{version}}\
+if [ -f dist/build/libHS%{pkgname}-%{pkgver}.a ]; then\
 %cabal haddock --html %{!?without_hscolour:%(if [ -x %{_bindir}/HsColour ]; then echo --hyperlink-source; fi)} --hoogle\
+fi\
 %endif\
 %{nil}