First, make sure with
  $ echo $PATH
that the directory of the Qt executables are in your PATH.
If not, add it, for example:
  $ export PATH=/opt/qt4/bin:$PATH

To compile KEuroCalc, type, as a normal user:
  $ mkdir build && cd build
  $ cmake -DCMAKE_INSTALL_PREFIX=/opt/kde4 ../keurocalc
  $ make
  (replace "/opt/kde4" with the path where KDE is installed,
   and "../keurocalc" with the path to the sources of KEuroCalc)

To install KEuroCalc, type, as root user:
  # make install

To run KEuroCalc, type, as a normal user again:
  $ keurocalc
