Found the following significant warnings:
  Mobius.bounds.c:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  ./core.h:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  ./least.squares.h:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  Mobius.bounds.c:168:41: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  Mobius.bounds.c:169:11: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  cdf.Choquet.c:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  constraints.c:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  ./constraints.h:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  core.c:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  heuristic.ls.c:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  heuristic.ls.c:117:47: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  heuristic.ls.c:117:49: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  heuristic.ls.c:122:4: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  heuristic.ls.c:122:8: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  heuristic.ls.c:124:59: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  heuristic.ls.c:125:55: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  heuristic.ls.c:125:64: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  heuristic.ls.c:128:42: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  least.squares.c:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  ./Mobius.bounds.h:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  least.squares.c:58:28: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  least.squares.c:59:28: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  least.squares.c:121:65: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  min.dist.c:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  ./min.dist.h:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  min.var.c:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  ./min.var.h:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
  moments.Choquet.c:3:13: warning: invalid UTF-8 in comment [-Winvalid-utf8]
See '/home/hornik/tmp/R.check/r-devel-clang/Work/PKGS/kappalab.Rcheck/00install.out' for details.