abs_builddir="$(pwd)" || fail "$0: cannot determine working directory"
abs_srcdir="$(cd $srcdir && pwd)" || fail "$0: invalid source directory $srcdir"
test "$abs_srcdir" = "$abs_builddir" && srcdir=.
abs_builddir="$(pwd)" || fail "$0: cannot determine working directory"
abs_srcdir="$(cd $srcdir && pwd)" || fail "$0: invalid source directory $srcdir"
test "$abs_srcdir" = "$abs_builddir" && srcdir=.