Add cell-aware cross-compilation arguments#239
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dpc
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| mergeArgs = | ||
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| buildInputs = (left.buildInputs or [ ]) ++ (right.buildInputs or [ ]); |
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This file seems to be redoing bunch of stuff we already have. Is there point to it that I'm missing? If so, it should be documented and explained.
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Posted by Tau
You’re right that the original fixture duplicated too much. Its non-obvious purpose was to run a nested evaluator: pure Nix cannot tell us how many times argsFor was forced, and builtins.tryEval cannot inspect exception text.
I replaced it with a smaller documented adapter that only supplies args, scalar overrideArgs, and mapWithProfiles. Package-role, capability, and merge behavior now stays on the existing real enhanced-Crane test path.
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Add one optional, cell-aware `argsFor` resolver to `craneMultiBuild` so projects can select dependency artifacts for each existing target cell without changing Flakebox's manual Cargo-cross model. Resolve common project arguments once per cell before profile mapping and merge them through the existing `overrideArgs`/`mergeArgs` path. Preserve existing callbacks, selectors, output paths, and behavior when callers omit the resolver. ### Details Attach explicit dependency-role contexts to built-in toolchains. Native cells expose the native `pkgsBuildHost`, `pkgsHostTarget`, and `pkgsBuildBuild` roles; ordinary Nixpkgs cross cells expose those roles from their cross package set. Android and `wasm32-unknown-unknown` expose no false target universe, and `capabilities.targetBuildInputs` is derived from the availability of the target-library role. Missing role access reports the toolchain/cell and role lazily, so custom toolchains without a context remain usable until their resolver requests scoped packages. Document the public resolver contract, existing merge precedence, and the explicit-artifact boundary of the manual Cargo-cross model. Add evaluation coverage for native and x86_64-to-AArch64 role selection, custom/wasm/Android contextual diagnostics, capability-based filtering, three-layer argument precedence, Darwin portability, and exactly one resolver invocation per cell rather than per profile. The observable invocation-count and exception-text contracts use a compact, documented nested-evaluator adapter because pure Nix cannot expose either property; all package-role, capability, and merge behavior remains tested against the real enhanced Crane library. A comprehensive architecture, judgment, maintainability, and reliability review initially found Darwin-incompatible test selection, inaccurate `depsBuildBuild` merge documentation, weak invocation/capability/diagnostic coverage, and duplicated capability state. Those issues were fixed and re-review passed. A later inline review correctly noted that the first evaluator fixture reproduced too much Crane and merge infrastructure; it was replaced with the minimal adapter described above. The maintainability, reliability, and judgment re-review passed with no remaining findings. `nix build -L .#checks.x86_64-linux.craneMultiBuildTests`, all four supported-system focused check evaluations, `nix flake check --no-build --no-write-lock-file`, treefmt, and selfci pass. An attempted OpenSSL/pkg-config AArch64 build reached target OpenSSL discovery through the selected role scopes, then hit the existing linker policy at the time: AArch64 `ld.bfd` rejected `-Wl,--compress-debug-sections=zstd`. The behavioral link check remains outside this dependency-selection change rather than making PR rustshop#239 depend on unrelated linker/LLVM work.
Add one optional, cell-aware `argsFor` resolver to `craneMultiBuild` so projects can select dependency artifacts for each existing target cell without changing Flakebox's manual Cargo-cross model. Resolve common project arguments once per cell before profile mapping and merge them through the existing `overrideArgs`/`mergeArgs` path. Preserve existing callbacks, selectors, output paths, and behavior when callers omit the resolver. ### Details Attach explicit dependency-role contexts to built-in toolchains. Native cells expose the native `pkgsBuildHost`, `pkgsHostTarget`, and `pkgsBuildBuild` roles; ordinary Nixpkgs cross cells expose those roles from their cross package set. Android and `wasm32-unknown-unknown` expose no false target universe, and `capabilities.targetBuildInputs` is derived from the availability of the target-library role. Missing role access reports the toolchain/cell and role lazily, so custom toolchains without a context remain usable until their resolver requests scoped packages. Document the public resolver contract, existing merge precedence, and the explicit-artifact boundary of the manual Cargo-cross model. Add evaluation coverage for native and x86_64-to-AArch64 role selection, custom/wasm/Android contextual diagnostics, capability-based filtering, three-layer argument precedence, Darwin portability, and exactly one resolver invocation per cell rather than per profile. The observable invocation-count and exception-text contracts use a compact, documented nested-evaluator adapter because pure Nix cannot expose either property; all package-role, capability, and merge behavior remains tested against the real enhanced Crane library. Add an x86_64-to-AArch64 behavioral check with a small OpenSSL Rust binary. It asserts that `argsFor` selects `pkgsBuildHost.pkg-config` and `pkgsHostTarget.openssl`, executes the selected pkg-config wrapper, completes Crane dependency and package builds, and inspects the resulting binary, its `NEEDED` libssl entry, its target-OpenSSL `RUNPATH`, and libssl itself as AArch64 ELF artifacts. A comprehensive architecture, judgment, maintainability, and reliability review initially found Darwin-incompatible test selection, inaccurate `depsBuildBuild` merge documentation, weak invocation/capability/diagnostic coverage, and duplicated capability state. Those issues were fixed and re-review passed. A later inline review correctly noted that the first evaluator fixture reproduced too much Crane and merge infrastructure; it was replaced with the minimal adapter described above, and re-review passed. Review of the behavioral check found that its first path assertion was not confined to `RUNPATH`; the check now extracts and verifies that entry specifically, and final re-review passed with no remaining findings. `nix build -L .#checks.x86_64-linux.craneMultiBuildTests`, `nix build -L .#checks.x86_64-linux.cellAwareCrossInputs`, all four supported-system focused check evaluations, `nix flake check --no-build --no-write-lock-file`, treefmt, and selfci pass. The behavioral link check became feasible after the independent cross-linker compression fix merged on master; this change contains no linker-policy workaround.
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Posted by Tau
Summary
Add a cell-aware
argsForresolver tocraneMultiBuild. Projects can select the correct dependency artifacts for each existing target cell without replacing Flakebox's manual Cargo-cross model or changing its output matrix.Details
argsForruns once per toolchain/target cell before profile mapping. Its result flows through the existingoverrideArgs/mergeArgspath.Built-in cells expose explicit dependency-role package scopes:
nativeBuildInputsthroughpkgsBuildHostbuildInputsthroughpkgsHostTargetdepsBuildBuildthroughpkgsBuildBuildNative cells expose the corresponding native roles. Android and
wasm32-unknown-unknowndo not pretend to have a Nixpkgs target-package universe; unsupported role access fails lazily with the cell and missing role. Existing callers and custom toolchains remain unchanged when they do not use scoped packages.The change documents resolver semantics and merge precedence. Evaluation coverage includes native and AArch64 role selection, custom toolchains, unsupported-target diagnostics, capability filtering, Darwin evaluation, argument precedence, and once-per-cell evaluation.
The x86_64→AArch64 behavioral check uses a small OpenSSL Rust binary. It proves that
argsForselectspkgsBuildHost.pkg-configandpkgsHostTarget.openssl, executes the selected cross pkg-config wrapper, completes Crane dependency and package builds, and verifies:NEEDEDlibssl entry;RUNPATHselects target OpenSSL;The earlier cross-linker blocker is fixed independently by merged PR #240; this change contains no linker-policy workaround.
Reviewers can validate the change with
nix develop -c selfci check --candidate swtvruqz.