我正在尝试使用SRAdb package从NCBI SRA存储库下载RNASeq数据。我始终收到以下错误：
getSRAfile( in_acc = c("SRR2033366", "SRR2033446"),
sra_con = sra_con,
destDir = getwd(),
fileType = 'sra',
srcType = 'ftp',
makeDirectory = FALSE,
method = 'curl',
ascpCMD = NULL)
Error in if (is.na(sra_acc$run[i])) { : argument is of length zero