[Nix-dev] unable to delete a store path

[Mathijs Kwik]

On Wed, Sep 26, 2012 at 2:10 PM, Shea Levy <shea at shealevy.com> wrote:
> On 09/26/2012 08:07 AM, Mathijs Kwik wrote:
>>
>> On Wed, Sep 26, 2012 at 1:55 PM, Shea Levy<shea at shealevy.com>  wrote:
>>>
>>> If you do give up, before manually deleting it try nix-store --delete
>>> --ignore-liveness. That bypasses gcroots but fails if there's another
>>> path
>>> in the path's referrers (so it shouldn't fail in your case, but it might
>>> since this seems like a bug).
>>
>> Now it gets even weirder. I tried a normal --delete again and it worked!
>> With some output though:
>> ~% nix-store --delete
>> /nix/store/q6qapspkz2g4jlgnagiabrfvw32say9v-xine-lib-1.2.2
>> finding garbage collector roots...
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/lplg6g967ms0j3dvlsdq7am7iqa9vamh' to
>> `/tmp/nix-build.WKZR3u/result'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/yfjm7r5hfa2hfizqmllhyr0z25igwnwx' to
>> `/tmp/nix-build.aMDbJE/result'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/pyxwi92798bh8fzk5l1hs97yhfhk0prw' to
>> `/tmp/nix-build.jrGerR/result'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/cabj712wjp6xq2p9i9k4i80sjv0m475i' to
>> `/tmp/nix-build.o57rAD/derivation'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/hc4wifhj2vgxwn1psngn3avpwbapqfxk' to
>> `/tmp/nix-build.VCPc_z/result'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/xiv7rnq7bhnbbbvv5gslvkzm9yn3820k' to
>> `/tmp/nix-build.WKZR3u/derivation'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/0kn7llb10pfyjgqliap4lcn8a03vb5kv' to
>> `/tmp/nix-build.VCPc_z/derivation'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/0j0lpqh6mq9kpi1lrirlfxq26q7zxh54' to
>> `/tmp/nix-build.Zv7p2Q/result'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/6bg5afp1sw1f490il4ji8pn8495ww712' to
>> `/tmp/nix-build.jrGerR/derivation'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/b1z1kmlwk1q8qndgs39xfsdfb78gnklv' to
>> `/tmp/nix-build.Zv7p2Q/derivation'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/4hawd1693c6vwdbrijm4blr3703nsk53' to
>> `/tmp/nix-build.o57rAD/result'
>> removing stale link from
>> `/nix/var/nix/gcroots/auto/nzkfzlimxk99ylrka45xgzhwwqjayvql' to
>> `/tmp/nix-build.aMDbJE/derivation'
>> invalidating `/nix/store/q6qapspkz2g4jlgnagiabrfvw32say9v-xine-lib-1.2.2'
>> deleting
>> `/nix/store/q6qapspkz2g4jlgnagiabrfvw32say9v-xine-lib-1.2.2-gc-5066'
>> deleting unused links...
>> note: currently hard linking saves 486.02 MiB
>> 1 store paths deleted, 7.93 MiB freed
>>
>>
>> This is very strange. Apart from trying the commands you and Marc gave
>> me to try, I haven't performed any nix-actions since I reported my
>> problem.
>> Somehow these auto-gcroots are now freed?
>
>
> IIUC that stale link stuff is for indirect gcroots whose targets have
> disappeared. Since most of those targets are in /tmp/nix-build*, perhaps you
> were in the middle of a build before and that's why the path was kept?

My /tmp is on tmpfs so it must be relatively new (booted this morning).
I have done a rebuild today, but without interruption.
Also, now the path is gone, I can't find any traces of xine-lib in my
store anymore, so the rebuild seems unrelated.
I have no idea how long the path itself has been there. Might have
been a few months :)

Bit strange all in all. I will keep an eye out for similar issues.
Thanks for your help though. I learned a bit more about nix this way.