Comment 3 for bug 121834

The problem come from the p_gcc var in case og cross compiling, see in debian/rules2:

ifndef DEB_CROSS
  p_base = gcc$(pkg_ver)-base
  p_gcc = gcc$(pkg_ver)
  p_cpp = cpp$(pkg_ver)
  p_cppd = cpp$(pkg_ver)-doc
  p_cxx = g++$(pkg_ver)
  p_doc = gcc$(pkg_ver)-doc
  p_lgcc = libgcc$(GCC_SONAME)
else
  # only triggered if DEB_CROSS_INDEPENDENT set
  p_base = gcc$(pkg_ver)$(cross_bin_arch)-base
  p_cpp = cpp$(pkg_ver)$(cross_bin_arch)
  p_gcc = gcc$(pkg_ver)$(cross_bin_arch)
  p_cxx = g++$(pkg_ver)$(cross_bin_arch)
endif

Have to modify variable $(cross_bin_arch), then in debian/rules.defs

ifdef DEB_CROSS
  cross_bin_arch := -$(TARGET_ALIAS)
  cross_lib_arch := -$(DEB_TARGET_ARCH)-cross
endif

For a first test I've just added two others tr on cross_bin_arch and cross_lib_arch, if works will at least modify consequently TARGET_ALIAS ifdef DEB_CROSS.