Bug 1835424
| Summary: | rpm test transaction fails with upgrade of package that uses %pretrans to replace a symlink to another package's files with a directory | ||||||||||
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| Product: | [Fedora] Fedora | Reporter: | Stephen Gallagher <sgallagh> | ||||||||
| Component: | rpm | Assignee: | Michal Domonkos <mdomonko> | ||||||||
| Status: | CLOSED DUPLICATE | QA Contact: | Fedora Extras Quality Assurance <extras-qa> | ||||||||
| Severity: | high | Docs Contact: | |||||||||
| Priority: | unspecified | ||||||||||
| Version: | 37 | CC: | dmach, fedora, ffesti, jmracek, jrohel, mblaha, ngompa13, packaging-team-maint, pkratoch, pmatilai, pmoravco, rpm-software-management, tdawson, vmukhame | ||||||||
| Target Milestone: | --- | Keywords: | Reopened | ||||||||
| Target Release: | --- | ||||||||||
| Hardware: | All | ||||||||||
| OS: | Linux | ||||||||||
| Whiteboard: | |||||||||||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |||||||||
| Doc Text: | Story Points: | --- | |||||||||
| Clone Of: | Environment: | ||||||||||
| Last Closed: | 2023-11-21 14:59:27 UTC | Type: | Bug | ||||||||
| Regression: | --- | Mount Type: | --- | ||||||||
| Documentation: | --- | CRM: | |||||||||
| Verified Versions: | Category: | --- | |||||||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||||||
| Embargoed: | |||||||||||
| Bug Depends On: | |||||||||||
| Bug Blocks: | 1828899, 2038302 | ||||||||||
| Attachments: |
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Reassigning to RPM; it turns out that the same error occurs if I run `rpm --test`. So there's a bug somewhere between the test transaction and the real transaction. ``` [root@75dffca6fbca noarch]# rpm --test -Uvh sgallagh-symlink-update-0-2.fc32.noarch.rpm Verifying... ################################# [100%] Preparing... ################################# [100%] file /opt/bug/package/etc/shells from install of sgallagh-symlink-update-0-2.fc32.noarch conflicts with file from package setup-2.13.6-2.fc32.noarch ``` Thanks for the nice reproducer! Rpm currently only allows %pretrans presence to escape file conflicts on test upgrade in the very specific case that the conflicting file would get removed on the transaction anyway. Typically this would be an older version of the package itself, which naturally gets removed on an upgrade. Here, the conflict is on a file owned by setup, which isn't going anywhere. Of course the conflict is actually caused by an intermediate symlink that would go away in this transaction, but rpm doesn't see that. Can't say offhand what, if anything, we can actually do about this (short of relaxing the %pretrans rule to cover more or less any conflict, which doesn't seem healthy) but at least the simple reproducer makes the case comprehensible. (In reply to Panu Matilainen from comment #2) > Thanks for the nice reproducer! > > Rpm currently only allows %pretrans presence to escape file conflicts on > test upgrade in the very specific case that the conflicting file would get > removed on the transaction anyway. Typically this would be an older version > of the package itself, which naturally gets removed on an upgrade. Here, the > conflict is on a file owned by setup, which isn't going anywhere. Of course > the conflict is actually caused by an intermediate symlink that would go > away in this transaction, but rpm doesn't see that. > > Can't say offhand what, if anything, we can actually do about this (short of > relaxing the %pretrans rule to cover more or less any conflict, which > doesn't seem healthy) but at least the simple reproducer makes the case > comprehensible. Well, the main problem here seems to be that RPM thinks it's removing /etc/shells when it's actually just removing the symlink to /etc/shells. That suggests to me that somewhere in the check, it's following the symlink instead of treating it as a file. Yes, like I said it's the symlink to /etc. Rpm simply treats a directory and a symlink to one as equal and doesn't generally consider whether it should follow something or not. This is a fundamental part of making various things work, but also causes these kind of problems. I think if we add some comments in the %pretrans we see what's really going on.
## An actual update
# rpm -Uvh sgallagh-symlink-update2-0-4.el8.noarch.rpm
Verifying... ################################# [100%]
PRETRANS : sgallagh-symlink-update2-0-4.el8
Preparing... ################################# [100%]
Updating / installing...
1:sgallagh-symlink-update2-0-4.el8 ################################# [ 50%]
Cleaning up / removing...
2:sgallagh-symlink-update2-0-3.el8 ################################# [100%]
## A test update
# rpm --test -Uvh sgallagh-symlink-update2-0-4.el8.noarch.rpm
Verifying... ################################# [100%]
Preparing... ################################# [100%]
file /opt/bug/package/etc/shells from install of sgallagh-symlink-update2-0-4.el8.noarch conflicts with file from package setup-2.12.2-5.el8.noarch
As we see, during the --test, the %pretrans isn't happening.
And you don't want it to happen.
Running scripts during a --test is all sorts of bad. It is no longer a test, it's the real thing, without the files being moved.
So, the whole %pretrans argument, if rpm is doing it correctly, seems to go out the window.
rpm is running %pretrans correctly.
But, during --test (which dnf calls) it isn't running %pretrans, which it shouldn't.
So, how to fix the problem.
A) have rpm treat symlinks to directories different. But according to comment #4 that breaks other things.
B) don't have dnf call --test before it does updates. That also leads to problems. I remember the days of half done updates.
C) Something else
I'll be honest, I don't know what C is yet. But it sure looks like that's what we need.
A promising work around is changing the link to point to a different directory. That directory can be part of the rpm. Using the example above, we start with #sgallagh-symlink-update3-0-1 /opt/bug/package/file1 /opt/bug/package/etc -> /etc And we can safely update to the following #sgallagh-symlink-update3-0-1 /opt/bug/package/file1 /opt/bug/package/etc -> /opt/bug/package/bundle-etc /opt/bug/package/bundle-etc/ /opt/bug/package/bundle-etc/shells That works for rpm -Uvh, rpm --test -Uvh, and dnf install or update Created attachment 1700647 [details]
Specfile to show example, that says when pretrans is run
Created attachment 1700648 [details]
Specfile that shows possible work around
This message is a reminder that Fedora 32 is nearing its end of life. Fedora will stop maintaining and issuing updates for Fedora 32 on 2021-05-25. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '32'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 32 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. Fedora 32 changed to end-of-life (EOL) status on 2021-05-25. Fedora 32 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed. This bug appears to have been reported against 'rawhide' during the Fedora 35 development cycle. Changing version to 35. *** Bug 2031013 has been marked as a duplicate of this bug. *** This message is a reminder that Fedora Linux 35 is nearing its end of life. Fedora will stop maintaining and issuing updates for Fedora Linux 35 on 2022-12-13. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a 'version' of '35'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, change the 'version' to a later Fedora Linux version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora Linux 35 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora Linux, you are encouraged to change the 'version' to a later version prior to this bug being closed. Just FTR, this is a dupe of Bug 1936422 and also is tracked upstream: https://github.com/rpm-software-management/rpm/issues/1458 It's not a one-off/easy fix and requires more thought and perhaps more substantial (RFE level) work so I'll close this one. When/if this is fixed upstream, it'll eventually trickle down into Fedora. *** This bug has been marked as a duplicate of bug 1936422 *** |
Created attachment 1688167 [details] Specfile to reproduce the bug Description of problem: DNF falsely claims a conflict when attempting to upgrade a package that is replacing a symlink to a directory belonging to a different package with its own directory (for example, a package that has forked and modified a bundled dependency and can no longer refer to the system copy). Version-Release number of selected component (if applicable): dnf-4.2.21-1.fc32.noarch libdnf-0.47.0-1.fc32.x86_64 How reproducible: Every time Steps to Reproduce: 1. Build the specfile provided as an attachment to this bug twice, once normally and once with `--with pretrans` 2. Install sgallagh-symlink-update-0-1.fc32 on the system. Verify that /opt/bug/package/etc is a symlink to /etc 3. Use DNF to attempt to update to sgallagh-symlink-update-0-2.fc32. Actual results: Error: Transaction test error: file /opt/bug/package/etc/shells from install of sgallagh-symlink-update-0-2.fc32.noarch conflicts with file from package setup-2.13.6-2.fc32.noarch Expected results: The upgrade should complete successfully, because the %pretrans scriptlet properly removes the symlink before the RPM transaction attempts to replace it. Additional info: It works fine when upgrading directly with `rpm -Uvh`: ``` [root@4bf814bd44f0 /]# rpm -Uvh /distgit/RPMS/noarch/sgallagh-symlink-update-0-2.fc32.noarch.rpm Verifying... ################################# [100%] Preparing... ################################# [100%] Updating / installing... 1:sgallagh-symlink-update-0-2.fc32 ################################# [ 50%] Cleaning up / removing... 2:sgallagh-symlink-update-0-1.fc32 ################################# [100%] ``` This will affect a lot of Node.js packages in the near future, as the Node.js SIG is working on reworking packaging to be more compatible with upstream style (which emphasizes bundling).