Commit Graph
3 Commits
Author SHA1 Message Date
Maximilian Bosch de4cfec46a libstore: fix reporting output cycles on drvs with references to other drvs
Closes #1064

The culprit here is that `genGraphString` is only invoked with the
store-paths associated with the outputs of the derivation, so when
filling `dependents`, the `graph_data.find(p)` call would return the end
of the iterator when doing this for references to other store-paths.

As a result, the code wrote information behind the graph data-structure
causing a corruption. For me, this resulted in a SIGSEGV most of the
time and in a few cases in an uncaught `map::at`-exception as reported
by Niklas.

This patch changes two aspects of the original implementation:

* When filling `dependents` in the node-set, use `map.at()` instead of
  `map.find()->second`. The latter doesn't make any sense and was the
  cause of corrupting memory. The `at` would've made it far easier to
  spot this in the first place.

* Filter out store-paths that don't belong to a different output of the
  derivation when creating `outputGraph`. This variable is used on two
  places, `genGraphString` and for topological sorting.

  The latter already filters out store-paths from a different drv, so
  this is happening now when creating the variable in the first place
  such that `genGraphString` never ends up with corrupt data in the
  first place. This is the actual bugfix.

Implemented a regression-test for this case to be sure.

Change-Id: Ie02144d89c32b0a776cb1ece0601d0229315ebc3
(cherry picked from commit 0a5f474a25)
2025-12-08 07:20:51 +01:00
Maximilian Bosch e2641cb890 libstore/local-derivation-goal: show tree with references that lead to an output cycle
Closes #551

This adds a special accessor that falls back to checking if a store-path
exists within a chroot if it's not a valid path. That way,
`genGraphString` can find out which files have which references before
the outputs are registered.

Change-Id: I03c9d508fa3c72e5c262194461a25d71f3f4de15
2025-08-24 01:15:15 +02:00
Maximilian Bosch 312e90f4b6 tests: add small testcase for output cycle detection
Change-Id: I186937dfbca4d051e5ad860239720816429a0a8e
2025-08-23 16:23:35 +02:00