Re: Numerical result out of range in rdb 2.2.6?

[Eric L.]

Hi Derek,

I won't be very helpful but the issue appears within the open function 
of Python, so not in the code of rdiff-backup (which doesn't mean that 
we can't do anything about it, just that it is more difficult to 
troubleshoot).

From the look of it and knowing what I know about Android and MTP, I 
guess an issue with either a user/group ID, time stamp or access rights, 
or even the file descriptor.
Android looks like POSIX but it doesn't comply to it so you might have 
hit one of those corner cases (why now and not before, no clue).
I could also imagine that you have an issue with the MTP file system 
giving up on rdiff-backup opening and closing files with high frequency. 
MTP isn't known to be the most performant thing in the world, to say the 
least.

Two more or less helpful hints:

1. solving the issue would probably require reproducing it with Python 
code to understand the exact cause, before I would be potentially able 
to find a workaround
2. as an alternative to MTP (urk!), I've been playing with rdiff-backup 
on my smart-phone with SSH using Termux. I wouldn't say that it was 
production grade, but it worked (I didn't pursue the idea because I 
didn't need it, I was just playing around).

KR, Eric

On 14.06.2024 16:26, Derek Atkins wrote:
> Hi,
>
> I've recently been attempting to backup my phone using rdiff backup.  
> Last
> backup was successful 3 months ago (yeah, yeah, I know -- I should 
> backup
> more often).
>
> I use mtpfs-simple to mount the phone as a file system on my Fedora-38
> system and use rdiff-backup (rdiff-backup-2.2.6-3.fc38.x86_64) to sync 
> it
> to my laptop.  However, lately RDB has been barfing during the backup.
> The exact file where it errors out changes from attempt to attempt, but
> the error always appears to be the same:
>
> WARNING: Exception '[Errno 34] Numerical result out of range:
> b'/path/to/file'' raised of class '<class 'OSError'>':
>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/robust.py", 
> line
> 94, in check_common_error
>     return function(*args)
>            ^^^^^^^^^^^^^^^
>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/rpath.py", 
> line
> 1129, in open
>     return open(self.path, mode)
>            ^^^^^^^^^^^^^^^^^^^^^
>
> Traceback (most recent call last):
>   File "/usr/bin/rdiff-backup", line 33, in <module>
>     sys.exit(load_entry_point('rdiff-backup==2.2.6', 'console_scripts',
> 'rdiff-backup')())
>
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>   File "/usr/lib64/python3.11/site-packages/rdiffbackup/run.py", line 
> 35,
> in main
>     sys.exit(main_run(sys.argv[1:]))
>              ^^^^^^^^^^^^^^^^^^^^^^
>   File "/usr/lib64/python3.11/site-packages/rdiffbackup/run.py", line 
> 108,
> in main_run
>     ret_val |= conn_act.run()
>                ^^^^^^^^^^^^^^
>   File
> "/usr/lib64/python3.11/site-packages/rdiffbackup/actions/backup.py",
> line 154, in run
>     backup.mirror_and_increment_compat200(
>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/backup.py", 
> line
> 53, in mirror_and_increment_compat200
>     DestS.patch_and_increment(dest_rpath, source_diffiter, inc_rpath)
>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/backup.py", 
> line
> 208, in patch_and_increment
>     for diff in rorpiter.FillInIter(source_diffiter, dest_rpath):
>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/rorpiter.py",
> line 406, in FillInIter
>     for rp in rpiter:
>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/backup.py", 
> line
> 134, in get_diffs
>     attach_snapshot(diff_rorp, src_rp)
>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/backup.py", 
> line
> 96, in attach_snapshot
>     fileobj = robust.check_common_error(
>               ^^^^^^^^^^^^^^^^^^^^^^^^^^
>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/robust.py", 
> line
> 94, in check_common_error
>     return function(*args)
>            ^^^^^^^^^^^^^^^
>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/rpath.py", 
> line
> 1129, in open
>     return open(self.path, mode)
>            ^^^^^^^^^^^^^^^^^^^^^
> OSError: [Errno 34] Numerical result out of range: b'/path/to/file'
>
>
> The command-line is:
>
> rdiff-backup --exclude-globbing-filelist /path/of/my-excludes
> /path/to/source-dir /path/of/backup-dir
>
>
> Any ideas?
>
> Version 2.2.6 is the latest version available on F38.
>
> -derek