[Backport 2.33-maintenance] Fix destruction of DerivationBuilder implementations#15078
Merged
Ericson2314 merged 1 commit intoJan 25, 2026
Conversation
This unsures that we call the correct virtual functions when destroying a particular
DerivationBuilder.
Usually the order of destructors is in the reverse order of inheritance:
ChrootLinuxDerivationBuilder -> ChrootDerivationBuilder -> DerivationBuilderImpl
autoDelChroot was being destroyed before the DerivationBuilderImpl::killChild was
run and it would fail to clean up the chroot directory, since there were still processes
writing to it. Note that ChrootLinuxDerivationBuilder::killSandbox was never run in
the interrupted case at all, since virtual functions in destructors do not call derived class
methods.
I could reproduce the issue with the following derivation:
let
pkgs = import <nixpkgs> { };
in
pkgs.runCommand "chroot-cleanup-race" { } ''
mkdir -p $out
for i in $(seq 1 200); do
(
mkfifo $out/fifo$i
cat $out/fifo$i > /dev/null &
while true; do
: > $out/file$i
done
) &
done
sleep 0.05
echo done > $out/main
''
While interrupting it manually when it would hang.
Wrapping the unique pointer in a custom deleter function we can run all
of the necessary clean up code consistently and calling the right virtual
functions. Ideally we'd have a lint that bans the usage of virtual functions
in destructors completely.
(cherry picked from commit b752c5c)
Ericson2314
approved these changes
Jan 24, 2026
Ericson2314
added
the
backport 2.32-maintenance
|
Backport failed for Please cherry-pick the changes locally and resolve any conflicts. git fetch origin 2.32-maintenance
git worktree add -d .worktree/backport-15078-to-2.32-maintenance origin/2.32-maintenance
cd .worktree/backport-15078-to-2.32-maintenance
git switch --create backport-15078-to-2.32-maintenance
git cherry-pick -x 70ecd8c8a9123bb6e79a19559fc1b5a5310ddbc8 |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Motivation
Manual backport of #15072 to 2.33-maintenance.
(cherry picked from commit b752c5c)
Context
Add 👍 to pull requests you find important.
The Nix maintainer team uses a GitHub project board to schedule and track reviews.