Rust wrapper missing with prebuilt dependencies

scope: generic · severity: trap · confidence: proven · subsystem: build

Evidence

https://github.com/porthole-dev/pmbootstrap/commit/276919b37b355fafa2773e23aca2573595708c33; https://github.com/porthole-dev/pmaports/actions/runs/36642456650/job/109657801335; https://github.com/porthole-dev/pmaports/actions/runs/36661078089/job/109716081284

Symptom — Cargo fails in prepare() with could not execute process /usr/bin/sccache rustc -vV and No such file or directory. C dependencies have already built successfully in the same native chroot.

Cause — pmbootstrap enables RUSTC_WRAPPER when compiler caching is on. Installing sccache only during the chroot’s first initialization misses Rust packages reached after a C package. Detecting Rust from the source-build queue also misses compiler dependencies already supplied as binary packages.

What to do — Check the current APKBUILD’s declared build dependencies. Install sccache when caching is enabled and those dependencies require Rust, Cargo or cargo-auditable, even if the chroot is already initialized and the source dependency queue is empty. Keep the chroot-local server socket.

Control — test/build/test_native_sccache.py executes the real setup block with initialization returning false, Cargo declared, and an empty source queue. The queue-based implementation fails; the recipe-based implementation passes. The failing and successful Obscura APK jobs above provide the execution check.