There seems to be a (rare) race in parallel builds where make for some
reason decides to update the libobj symlink after it already exists,
which fails. I can't reproduce the failure, but deleting the symlink
(if one exists) before creating it should avoid the issue.
print <<EOF;
${am_dir_prefix}libobj_la_SOURCES += $distfile
$ltdl_dir/$base.lo: $ltdl_dir/${am_dir_prefix}libobj_la-$base.lo
+\t\$(AM_V_at)-rm -f \$@
\t\$(AM_V_at)(cd \$(\@D) && \$(LN_S) ${am_dir_prefix}libobj_la-\$(\@F) \$(\@F))
EOF