Because each FTP server program has its own quirks and unique interpretation of the FTP protocol, most bugs in NcFTP Client are caused by an unexpected interaction with a particular type of server software. What helps us fix our own bugs or work-around server bugs is the actual FTP protocol dialogue that was exchanged, and we call this a FTP protocol trace.
NcFTP Client (the interactive ncftp program) automatically stores the trace in the file $HOME/.ncftp/trace. Simply run ncftp, recreate the problem, quit the program, and inspect the $HOME/.ncftp/trace file.
The other programs (ncftpget, ncftpput, etc.) have a special command-line option (-d) which saves the trace to a log file. For example, if your original command was:
A sample $HOME/.ncftp/trace file follows. When sending us your bug report, please include a trace with your e-mail. This will help us diagnose the problem, and recreate the problem as closely as possible.
SESSION STARTED at:  Wed Aug 27 14:18:41 2003
   Program Version:  NcFTP 3.1.6/102 Aug 25 2003, 08:04 PM
   Library Version:  LibNcFTP 3.1.6 (August 24, 2003)
        Process ID:  1174
          Platform:  linux-x86
          Hostname:  pc.example.com  (rc=3)
          Terminal:  vt100
14:18:41  Fw: firewall.example.com  Type: 0  User: joseph  Pass: ********  Port: 21
14:18:41  FwExceptions: .example.com,localhost,localdomain
14:18:51  > o ftp.example.com
14:18:51  Resolving ftp.example.com...
14:18:51  Connecting to 172.16.75.25...
14:18:51  LibNcFTP 3.1.6 (August 24, 2003) compiled for linux-x86
14:18:51  Uname: Linux|pc|2.4.20|#2 SMP Mon Feb 17 15:36:45 CST 2003|i686
14:18:51  Glibc: 2.2.4 (stable)
14:18:51  Remote server is running wu-ftpd.
14:18:51  Logging in...
14:18:51  220: ftp.example.com FTP server (Version wu-2.6.1-18) ready.
14:18:51  Connected to 172.16.75.25.
14:18:51  Cmd: USER anonymous
14:18:51  331: Guest login ok, send your complete e-mail address as password.
14:18:51  Cmd: PASS joseph@example.com
14:18:51  Logging in...
14:18:51  230: Guest login ok, access restrictions apply.
14:18:51  Cmd: PWD
14:18:51  257: "/" is current directory.
14:18:51  Logged in to 172.16.75.25 as anonymous.
14:19:31  > get secretfile.txt
14:19:31  Cmd: SIZE secretfile.txt
14:19:31  550: secretfile.txt: No such file or directory.
14:19:31  Cmd: PASV
14:19:31  227: Entering Passive Mode (172,16,75,25,49,39)
14:19:31  Cmd: RETR secretfile.txt
14:19:31  550: secretfile.txt: No such file or directory.
14:19:44  > quit
14:19:46  Cmd: QUIT
14:19:46  221: You have transferred 0 bytes in 0 files.
14:19:46       Total traffic for this session was 1011 bytes in 0 transfers.
14:19:46       Thank you for using the FTP service on ftp.example.com.
SESSION ENDED at:    Wed Aug 27 14:19:46 2003