I've been running ktorrent for quite a while, but under 3.5.9 - and the recent Debian-unstable introduction of KDE 4 has brought on a myriad of ... interesting experiences.

KTorrent self-reports as version 3.2.2

Debian reckons it's actually 3.2.1+dfsg.1-1

As per another thread I discovered from 2006, about a Bus error bug, I ran this through gdb and did a bt - the last section is shown below. Note the app crashes quite silently - only if you do a nofork do you see the Bus error message at all. It crashes while just sitting in the background doing its thing - no verify, no add, no any user interaction.

I'm on an MSI Wind - so, a modest 1.6GHz CPU, 2GB RAM. 1.5GB swap - of which I'm using about 4MB. I've got maybe a dozen torrents open - 8 or 9 are in upload status.

(no debugging symbols found)
[New Thread 0xb2914b90 (LWP 6166)]
[New Thread 0xb2113b90 (LWP 6167)]
[New Thread 0xb17ffb90 (LWP 6168)]
[Thread 0xb17ffb90 (LWP 6168) exited]
[Thread 0xb4434b90 (LWP 6165) exited]

Program received signal SIGBUS, Bus error.
[Switching to Thread 0xb5a06700 (LWP 6158)]
0xb66f1481 in memcpy () from /lib/i686/cmov/libc.so.6
(gdb) bt
#0 0xb66f1481 in memcpy () from /lib/i686/cmov/libc.so.6
#1 0xb7e8b94f in ?? () from /usr/lib/libbtcore.so.10
#2 0xb7e93155 in bt::Downloader::pieceReceived () from /usr/lib/libbtcore.so.10
#3 0xb7e7a3af in bt::PeerManager::pieceReceived () from /usr/lib/libbtcore.so.10
#4 0xb7e78c71 in ?? () from /usr/lib/libbtcore.so.10
#5 0xb7e82a0e in ?? () from /usr/lib/libbtcore.so.10
#6 0xb7e78591 in ?? () from /usr/lib/libbtcore.so.10
#7 0xb7e7c508 in bt::PeerManager::update () from /usr/lib/libbtcore.so.10
#8 0xb7eb22cd in bt::TorrentControl::update () from /usr/lib/libbtcore.so.10
#9 0x0806c076 in _start ()

I discovered the problem was a dodgy file that had become corrupted (presumably after one of the many crashes that KDE4's granted me) this week.

I did this by cat'ing each partial download component out to dev/null and looked for any problems - a couple of the files had i/o errors during the cat process. I removed those files, and re-started ktorrent, and all is well.

Not sure how bad i/o errors are at an application layer - they might not be catchable? If they are, then obviously it'd be nicer if ktorrent was a tad more informative about the nature of its problem.