Apply first changes from Fedora submission pre-review by @vondruch

Ref:

    https://bugzilla.redhat.com/show_bug.cgi?id=1586291#c1

slop.spec.in

 BuildRequires: libXrender-devel
 BuildRequires: mesa-libEGL-devel
 
-Requires: libslopy = %{version}-%{release}
 %description
 slop (Select Operation) is an application that queries for a selection
 from the user and prints the region to stdout.
 
 %package -n libslopy
 Summary: Select Operation
-Group: System Environment/Libraries
 %description -n libslopy
 slop (Select Operation) is an application that queries for a selection
 from the user and prints the region to stdout.
 
 %package -n libslopy-devel
 Summary:    Select Operation
-Group: Development/Libraries
-Requires: libslopy = %{version}-%{release}
 %description -n libslopy-devel
 slop (Select Operation) is an application that queries for a selection
 from the user and prints the region to stdout.
 %autosetup -n %{name}-%{version}
 
 %build
-CXXFLAGS="${CXXFLAGS:-%{optflags}}"; export CXXFLAGS
-cmake -DCMAKE_INSTALL_PREFIX="/usr" ./
+%cmake .
 
 %install
 %make_install
 
-%post -n libslopy
-/sbin/ldconfig
-
-%postun -n libslopy
-/sbin/ldconfig
+%check
+ctest -V %{?_smp_mflags}
 
 %files
 %{_bindir}/slop