Make a distinction between source and build directories.
test_expect_equal "$result" "$output"
test_begin_subtest 'comparing existing to exported symbols'
-nm -P $TEST_DIRECTORY/../lib/libnotmuch.so | awk '$2 == "T" && $1 ~ "^notmuch" {print $1}' | sort | uniq > ACTUAL
-sed -n 's/^\(notmuch_[a-zA-Z0-9_]*\)[[:blank:]]*(.*/\1/p' $TEST_DIRECTORY/../lib/notmuch.h | sort | uniq > EXPORTED
+nm -P $NOTMUCH_BUILDDIR/lib/libnotmuch.so | awk '$2 == "T" && $1 ~ "^notmuch" {print $1}' | sort | uniq > ACTUAL
+sed -n 's/^\(notmuch_[a-zA-Z0-9_]*\)[[:blank:]]*(.*/\1/p' $NOTMUCH_SRCDIR/lib/notmuch.h | sort | uniq > EXPORTED
test_expect_equal_file EXPORTED ACTUAL
test_done