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raito 2a7a6cb85a fix(local-store): invalidate phantom referrers at garbage collection time
Sometimes, a path can disappear from the `ValidPaths` table (I have 23
such cases on my 1.4TB Nix store).

When this occurs and you try to run a garbage collection,
`queryReferrers` will report no referrer because it's performing a
*RIGHT JOIN* between `Refs` and `ValidPaths`, finally, when you issue
the deletion SQL statement, this will throw an uncaught exception from
SQLite side regarding a foreign key violation because `reference` in
`Refs` is a foreign key to `ValidPaths` (which we are trying to delete).

Why can this happen?

Two reasons:

* `PRAGMA foreign_keys=off;` will disable deletion on cascade.
* Trigger recursion *limits*, a deletion on cascade is a *trigger*, when
  a delete is issued and it triggers a bunch of deletion on cascade,
  there's a documented limit by SQLite: https://www.sqlite.org/limits.html#max_trigger_depth

  > Recursion limit on foreign key actions. The SQLITE_MAX_TRIGGER_DEPTH
  > and SQLITE_LIMIT_TRIGGER_DEPTH settings determine the maximum
  > allowable depth of trigger program recursion. For the purposes of
  > these limits, foreign key actions are considered trigger programs. The
  > PRAGMA recursive_triggers setting does not affect the operation of
  > foreign key actions. It is not possible to disable recursive foreign
  > key actions.

As I do not see easy ways to solve the root cause, garbage collection
should be self-healing in that regards, so I propose to invalidate
phantom referrers as we go.

As part of a work improving the consistency of the SQLite database, it
would make sense to count how many times this happen and try to find
ways to reproduce this issue.

Change-Id: I055a8a1d8c0e44d4388a411abe8e5a5e385f7b55
Signed-off-by: Raito Bezarius <raito@lix.systems>
2024-09-14 20:09:17 +02:00
.github .github: clean up stale things and wrong references 2024-06-12 15:34:23 -07:00
bench Add benchmarking scripts 2024-04-08 19:50:24 -07:00
contrib function-trace: always show the trace 2019-09-18 23:23:21 +02:00
doc repl: Patch editline to recognize Meta-Left & Meta-Right 2024-09-09 15:34:50 -07:00
maintainers rl-next: fix incorrect CL list syntax 2024-08-09 19:03:08 -07:00
meson clang-tidy: fix the fact that we are not linting headers properly 2024-08-28 09:52:08 -07:00
misc fish-completion: leave the shell prompt intact 2024-09-11 19:03:11 +02:00
nix-support editline: Vendor cl/1883 patch to recognize Alt+Left/Alt+Right 2024-09-11 09:35:00 -07:00
perl Merge changes Ib7c80826,I636f8a71,I67669b98 into main 2024-08-09 19:24:29 +00:00
releng releng: fix the git push 2024-08-07 21:46:44 -07:00
scripts remove the autoconf+Make buildsystem 2024-05-07 17:04:30 -06:00
src fix(local-store): invalidate phantom referrers at garbage collection time 2024-09-14 20:09:17 +02:00
subprojects rowan: 0.15.15 -> 0.15.16 2024-08-26 11:34:43 -07:00
tests fix(local-store): invalidate phantom referrers at garbage collection time 2024-09-14 20:09:17 +02:00
.clang-format Add pre-commit checks 2024-03-29 22:57:40 -07:00
.clang-tidy clang-tidy: write a lint for charptr_cast 2024-08-08 14:53:17 -07:00
.dir-locals.el .dir-locals.el: Set c-block-comment-prefix 2020-07-10 11:21:06 +02:00
.editorconfig add editorconfig for markdown 2024-05-24 02:22:44 +00:00
.envrc .envrc: remove MAKEFLAGS and use clang environment by default 2024-06-25 12:36:18 -06:00
.gitignore build: move to a Cargo workspace 2024-08-21 17:09:10 +00:00
.this-is-lix devShell: guard against running from another directory 2024-06-24 13:41:38 -07:00
Cargo.lock rowan: 0.15.15 -> 0.15.16 2024-08-26 11:34:43 -07:00
Cargo.toml build: move to a Cargo workspace 2024-08-21 17:09:10 +00:00
CONTRIBUTING.md chore: re-work the contribution guide 2024-05-07 01:28:35 +00:00
COPYING Add pre-commit checks 2024-03-29 22:57:40 -07:00
default.nix Format Nix code with nixfmt 2024-04-08 13:00:00 -07:00
docker.nix releng: support multiarch docker images 2024-06-09 20:33:24 -07:00
flake.lock update flake.lock 2024-07-26 11:22:34 +04:00
flake.nix forbid gcc for compilation, only allow clang 2024-09-09 01:48:20 +00:00
justfile build: implement clang-tidy using our plugin 2024-08-04 20:41:19 -07:00
meson.build forbid gcc for compilation, only allow clang 2024-09-09 01:48:20 +00:00
meson.options build: implement clang-tidy using our plugin 2024-08-04 20:41:19 -07:00
package.nix editline: Vendor cl/1883 patch to recognize Alt+Left/Alt+Right 2024-09-11 09:35:00 -07:00
README.md README: clarify license to match documentation 2024-08-10 16:11:58 -07:00
shell.nix shell.nix: conform to documentation 2024-05-27 16:47:40 +02:00
treefmt.toml Format Nix code with nixfmt 2024-04-08 13:00:00 -07:00
version.json Update version to 2.92 2024-08-12 18:06:08 -07:00

Lix

Lix is an implementation of Nix, a powerful package management system for Linux and other Unix systems that makes package management reliable and reproducible.

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