how to override a dependency build instructions ?

[teto]

first of all I feel sorry to ask since there is clear effort to provide a lot of documentation etc, congrats to that. It help me bootstrap the build quite fast.

TLDR: I am trying to override a transitive dependency build instructions of a crate in my cargo workspace.

I am trying to nix build wordbase, which depends on lindera, which has a build.rs that downloads files from the internet and then processes it. Nixpkgs has an exemple on how to patch the build.rs to work within a nix sandbox:
https://github.com/NixOS/nixpkgs/blob/e32cfd2e9abfe73cb3ed49c22bd1e29677ce4f9a/pkgs/applications/misc/pagefind/default.nix#L102

so "all" I have to do is in crane buildDepsOnly (?) process, be able to patch the build of the lindera-unidic crate specifically. I found #472 with the same question but I am not sure how to proceed. If I write a buildPackage specific for lindera-unidic, how do I make buildDepsOnly aware of this overriden lindera-unidic ? via overrideScope ?

Best regards

[ipetkov]

Hi @teto please take a look at https://crane.dev/patching_dependency_sources.html, this should give you some examples on how to patch any crate source in your dependency tree.

Hope this helps!

[teto]

It did help. The interface is a bit unusual for the nix world where you usually rely on overlays while in crane you setup a filter-based function. For future users with the same problem:

1. I first patched the lindera source (overrideVendorCargoPackage) to replace the internet url to a localhost one
2. I overrode the buildPhase in cargoArtifacts to start a local http server that served the file expected by lindera-unidic's build.rs

I was able to build nix build .#cargoArtifacts just fine with the patched lindera.
The problem is when I try to build the individual package "wordbase-cli", it attempts to rebuild lindera-unidic for a reason unknown to me and that build fails because it's missing my overrides

I've pushed my current code aecsocket/wordbase#4 if anyone is interested to look at it

[psionic-k]

I have a dependency that uses sqlx and it cannot seem to discover its .sqlx directory files. I think it's being filtered or it would be discovered. I've successfully gotten SQLX_OFFLINE set so that sqlx is attempting to use the prepared data rather than a database connection. Not sure how I would look inside the build of the dependency to confirm the .sqlx files or their absence. Also not sure what I would do to make sure they are retained when building the dependencies.

[psionic-k]

Found a workaround via configuration.

• In my top level crate's flake, add to args:

              SQLX_OFFLINE = "true";
              SQLX_OFFLINE_DIR = "sqlx";

• In the dependent that has some sqlx prepared data, move .sqlx -> sqlx

If the .sqlx folder was not filtered, only setting SQLX_OFFLINE would be necessary. Maybe it is worth adding an exception somewhere.

[kumawatdarshan]

@psionic-k I am running into the same problem. SQLX_OFFLINE_DIR doesn't to be having any effect though.
It seem to have no effect, even in the interactive shell.