+my $endpoint = $ENV{TEST_ENDPOINT} // 'all.mbox.gz';
+my $curl_opt = $ENV{TEST_CURL_OPT} // '';
+diag "TEST_JOBS=$JOBS TEST_ENDPOINT=$endpoint TEST_CURL_OPT=$curl_opt";
+
+# we set Host: to ensure stable results across test runs
+my @CURL_OPT = (qw(-HHost:example.com -sSf), split(' ', $curl_opt));