Failed writing header っていうエラメッセージが内部に出てて if(writeheader) { size_t wrote = writeheader(ptr, 1, chunklen, data->set.writeheader); if(CURL_WRITEFUNC_PAUSE == wrote) /* here we pass in the HEADER bit only since if this was body as well then it was passed already and clearly that didn't trigger the pause, so this is saved for later with the HEADER bit only */ return pausewrite(data, CLIENTWRITE_HEADER, ptr, len); if(wrote != chunklen) { failf (data, "Failed writing header"); return CURLE_WRITE_ERROR; } }