(Perhaps) temporary fix to pkgtools (cwrappers) build (configure).
Expanding  `` containing \ \n sequences looks to have been giving
problems.  I don't think this is the correct fix, but it will do
no worse harm than (perhaps) incorrectly calculating LINENO in this
kind of (rare) circumstance.  I'll look and see if there should be
a better fix later.

(kre)