rust postinst failed Expected exactly two files but found 1.

eccerr0r

I tried re-running and appears to have succeeded the second time but this was highly odd:

Kangie · Posted: Wed Nov 27, 2024 9:51 pm Post subject:

How interesting.

You seem to have hit an edge case in my attempt to work around breakage where `--keep-going` combined with a build failure could result in installing two copies of rust with the same version over the top of each other, but would leave the old copy installed (the uninstall action doesn't run until the next depclean).

The error here is that we attempt work around that in postinst, however if we don't find a match for a file (in this case we should find two files that match `/usr/lib/rust/1.80.1/lib/rustlib/i686-unknown-linux-gnu/lib/libcore-*`) we bail out rather than continue removing files.

I can't see a reason for you to have encountered this; libcore is not optional. We generate the list of files in preinst so we know it used to exist. Maybe you had a hash collision? Seems very unlikely but it's the best guess I have right now.

eccerr0r · Posted: Thu Nov 28, 2024 6:27 am Post subject:

As a personal note that might be helpful for others is that I was running --jobs=4 and indeed with --keep-going on my 10 core machine machine with distcc enabled. The first time around it gave up trying to --resume but it was able to finish when restarting emerge from the top.

The actions regarding the -r100 was weird and I think it eventually depcleaned.
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undrwater · Guru Joined: 28 Jan 2003 Posts: 314 Location: Caucasia

If there is interest, I have a full log of a very similar error, but not the exact one. Mine ends with:

eccerr0r · Posted: Sat Nov 30, 2024 4:59 pm Post subject:

Were you also using --jobs and --keep-going? Happen to know what was running at the time of failure perhaps?

At least we can probably assume that this is not a hash collision, I don't think hash collisions could happen this frequently?
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undrwater · Guru Joined: 28 Jan 2003 Posts: 314 Location: Caucasia

Kangie · Posted: Thu Dec 05, 2024 9:52 pm Post subject:

To close the loop here, it seems that fingerprints on rust libraries are not as unique as I had assumed. The ebuilds have been updated to show the apparent hash collisions but will continue in that case now.