| 17 Oct 2025 |
 John Ericson | as a I split things up | 15:46:56 |
| John Ericson | that is why DerivationBuilder doesn't register or return any path infos in the --check case | 15:47:27 |
| John Ericson | and I think it should stay that way | 15:47:30 |
| John Ericson | but we can make the caller just look them in the check case just for calling the hook | 15:47:43 |
| John Ericson | raboof: https://github.com/NixOS/nix/pull/14289 here's your fix! :) | 17:11:20 |
 raboof | Oh cool, thx! s/most/post/ 🙂. Will take it for a spin later this weekend! | 17:50:44 |
 fzakaria | Do the VM tests use a different derivation ? | 19:13:39 |
| fzakaria | My new test is passing .#componentTests but failing vmTests | 19:14:04 |
| fzakaria | I need to add python3 ... hmm;
Not sure why it's not there if it's in the componentTests | 19:16:10 |
| fzakaria | (I think I found it -- probably makes more sense to make it propagatedInputs but i just referenced it again) | 19:18:23 |
| fzakaria | okay gonna pickup another issue | 19:36:39 |
| fzakaria | i hit 60 min timeout on this PR | 20:23:07 |
| fzakaria | https://github.com/NixOS/nix/pull/14285 | 20:23:08 |
| fzakaria | but its all post tests :( | 20:23:15 |
| fzakaria | can someone re-run it ? | 23:18:34 |
| 18 Oct 2025 |
|  @ihar.hrachyshka:matrix.org left the room. | 00:11:45 |
|  turbio joined the room. | 00:21:51 |
| raboof | hmm I seems to remember in the past I seem to remember it would refuse to even start rebuilding in that case, with a message about "some outputs are not valid" or somesuch. I can't reproduce it right now, though, and might be confusing things. | 10:38:56 |
| raboof | things like https://cache.nixos.org/5yzw0vhkyszf2d179m0qfkgxmp5wjjx4.narinfo have no deriver but are in the cache anyway... do those ever get fetched? wouldn't they always be present locally because they're created as part of instantiation? | 15:26:14 |
 dramforever | you don't have to eval to download stuff from cache.nixos.org, there's nix copy | 15:27:54 |
| dramforever | uh, with --substitute-on-destination | 15:28:16 |
| dramforever | or you can nix copy --from https://cache.nixos.org a path | 15:28:31 |
| dramforever | but the point is no, it won't always be present locally | 15:28:55 |
| raboof | right, you can, but I wondered if/when that happens in practice | 15:30:58 |
| dramforever | --substitute-on-destination definitely happens in practice | 15:32:11 |
| fzakaria | anyone want to pair/hack tonight? | 20:11:25 |
| fzakaria | Question I was confused by Jeremy Fleischman (jfly) :
When calculating store-paths, Nix does "Hashing modulo fixed-output derivations" -- this makes sense since you want the store-path to be stable for multiple drvs for the FOD.
His question:
Can we replace all the inputDrvs with their store-path and also achieve the same thing?
(replace via the same massaging that we do for FODs)
| 20:54:21 |
| fzakaria | 
Download image.png | 21:04:07 |
| fzakaria | The part we are confused about:
B.drv may have many different A.drv ;
That's OK because eventually A.drv is replaced with A.outPath... BUT
C depends on B.drv ... wouldn't that path have changed since the contents of the drv can have N A.drv paths | 21:04:58 |
 Jeremy Fleischman (jfly) | My question is stronger than "can we?". I'm saying "mustn't we?" | 21:42:26 |
