Fix bad hollow-pipelining implementation#12
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dzbarsky merged 2 commits intohermeticbuild:mainfrom Apr 10, 2026
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This reverts commit 40c17fc.
Replace the process wrapper's rmeta-interception approach (kill rustc
after metadata emission) with rustc's -Zno-codegen flag, which produces
a hollow rlib containing metadata and MIR but no object code. This is
the same approach used by Buck2.
Key changes:
- Metadata action uses to
produce a hollow rlib (_meta.rlib) instead of raw .rmeta files
- Remove --rustc-quit-on-rmeta flag, LineOutput::Terminate, and all
associated kill logic from the process wrapper
- Full action emits only --emit=link (no longer includes metadata)
- Set RUSTC_BOOTSTRAP=1 on both metadata and full actions for SVH
compatibility (required for the unstable -Zno-codegen flag)
walter-zeromatter
changed the title
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Switches to using -Zno-codegen (same as buck2's rust rules) from the custom --rustc-quit-on-rmeta. This is a more supported path, which simplifies the process wrapper and fixes some issues that can happen due to killing an active rustc (See rust-lang/rust#143278)