Hangs at `waiting for lock on '/nix/store/...'` #797

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opened 2025-04-11 18:15:44 +00:00 by rbt · 3 comments

rbt commented

2025-04-11 18:15:44 +00:00

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Describe the bug

Sometimes, Lix leaves locks when a build is cancelled (?), leading to deadlocks:

$ nix develop --log-format multiline-with-logs
[0/87 built]
waiting for lock on '/nix/store/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-temporal-sdk-0.0.1.0', '/nix/store/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-temporal-sdk-0.0.1.0-doc', '/nix/store/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-temporal-sdk-0.0.1.0-hie'

(Hashes redacted.)

Workaround: On macOS, at least, runsudo rm /nix/store/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-temporal-sdk-0.0.1.0.lock.

Warning: One time I got frustrated enough that I did sudo rm /nix/store/*.lock. Do NOT do this, because you will remove Cargo.lock derivations and destroy your Nix store. I had to reinstall Nix entirely when I did that!

Steps To Reproduce

I don't have a reliable reproducer. I suspect that canceling evaluation with Ctrl-C causes this. I'm not sure if it's present on HEAD.

`nix --version` output

nix (Lix, like Nix) 2.92.0
System type: aarch64-darwin
Additional system types: x86_64-darwin
Features: gc, signed-caches
System configuration file: /etc/nix/nix.conf
User configuration files: /Users/wiggles/.config/nix/nix.conf:/etc/xdg/nix/nix.conf
Store directory: /nix/store
State directory: /nix/var/nix
Data directory: /nix/store/y9mgqlvgyh0ixd0vgyn1y4kjgsn2gw36-lix-2.92.0/share

## Describe the bug Sometimes, Lix leaves locks when a build is cancelled (?), leading to deadlocks: ``` $ nix develop --log-format multiline-with-logs [0/87 built] waiting for lock on '/nix/store/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-temporal-sdk-0.0.1.0', '/nix/store/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-temporal-sdk-0.0.1.0-doc', '/nix/store/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-temporal-sdk-0.0.1.0-hie' ``` (Hashes redacted.) Workaround: On macOS, at least, run`sudo rm /nix/store/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-temporal-sdk-0.0.1.0.lock`. **Warning:** One time I got frustrated enough that I did `sudo rm /nix/store/*.lock`. Do NOT do this, because you will remove `Cargo.lock` derivations and destroy your Nix store. I had to reinstall Nix entirely when I did that! ## Steps To Reproduce I don't have a reliable reproducer. I suspect that canceling evaluation with `Ctrl-C` causes this. I'm not sure if it's present on HEAD. ## `nix --version` output ``` nix (Lix, like Nix) 2.92.0 System type: aarch64-darwin Additional system types: x86_64-darwin Features: gc, signed-caches System configuration file: /etc/nix/nix.conf User configuration files: /Users/wiggles/.config/nix/nix.conf:/etc/xdg/nix/nix.conf Store directory: /nix/store State directory: /nix/var/nix Data directory: /nix/store/y9mgqlvgyh0ixd0vgyn1y4kjgsn2gw36-lix-2.92.0/share ```

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2025-04-11 18:15:44 +00:00

pennae commented

2025-04-11 18:18:21 +00:00

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that's quite possibly the known 2.92 deadlock we've fixed in main a while ago. in these cases you'll have processes that hold onto these locks left over, can you check for that next time it happens?