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…, r=Kobzol Move bootstrap configuration to library workspace This creates a new "dist" profile in the standard library which contains configuration for the distributed std artifacts previously contained in bootstrap, in order for a future build-std implementation to use. bootstrap.toml settings continue to override these defaults, as would any RUSTFLAGS provided. I've left some cargo features driven by bootstrap for a future patch. Unfortunately, profiles aren't expressive enough to express per-target overrides, so [this risc-v example](https://github.com/rust-lang/rust/blob/c8f22ca269a1f2653ac962fe2bc21105065fd6cd/src/bootstrap/src/core/build_steps/compile.rs#L692) was not able to be moved across. This could go in its own profile which Cargo would have to know to use, and then the panic-abort rustflags overrides would need duplicating again. Doesn't seem like a sustainable solution as a couple similar overrides would explode the number of lines here. We could use a cargo config in the library workspace for this, but this then would have to be respected by Cargo's build-std implementation and I'm not yet sure about the tradeoffs there. This patch also introduces a build probe to deal with the test crate's stability which is obviously not ideal, I'm open to other solutions here or can back that change out for now if anyone prefers. cc @Mark-Simulacrum rust-lang/rfcs#3874
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…, r=Kobzol Move bootstrap configuration to library workspace This creates a new "dist" profile in the standard library which contains configuration for the distributed std artifacts previously contained in bootstrap, in order for a future build-std implementation to use. bootstrap.toml settings continue to override these defaults, as would any RUSTFLAGS provided. I've left some cargo features driven by bootstrap for a future patch. Unfortunately, profiles aren't expressive enough to express per-target overrides, so [this risc-v example](https://github.com/rust-lang/rust/blob/c8f22ca269a1f2653ac962fe2bc21105065fd6cd/src/bootstrap/src/core/build_steps/compile.rs#L692) was not able to be moved across. This could go in its own profile which Cargo would have to know to use, and then the panic-abort rustflags overrides would need duplicating again. Doesn't seem like a sustainable solution as a couple similar overrides would explode the number of lines here. We could use a cargo config in the library workspace for this, but this then would have to be respected by Cargo's build-std implementation and I'm not yet sure about the tradeoffs there. This patch also introduces a build probe to deal with the test crate's stability which is obviously not ideal, I'm open to other solutions here or can back that change out for now if anyone prefers. cc @Mark-Simulacrum rust-lang/rfcs#3874
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…, r=Kobzol Move bootstrap configuration to library workspace This creates a new "dist" profile in the standard library which contains configuration for the distributed std artifacts previously contained in bootstrap, in order for a future build-std implementation to use. bootstrap.toml settings continue to override these defaults, as would any RUSTFLAGS provided. I've left some cargo features driven by bootstrap for a future patch. Unfortunately, profiles aren't expressive enough to express per-target overrides, so [this risc-v example](https://github.com/rust-lang/rust/blob/c8f22ca269a1f2653ac962fe2bc21105065fd6cd/src/bootstrap/src/core/build_steps/compile.rs#L692) was not able to be moved across. This could go in its own profile which Cargo would have to know to use, and then the panic-abort rustflags overrides would need duplicating again. Doesn't seem like a sustainable solution as a couple similar overrides would explode the number of lines here. We could use a cargo config in the library workspace for this, but this then would have to be respected by Cargo's build-std implementation and I'm not yet sure about the tradeoffs there. This patch also introduces a build probe to deal with the test crate's stability which is obviously not ideal, I'm open to other solutions here or can back that change out for now if anyone prefers. cc @Mark-Simulacrum rust-lang/rfcs#3874
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@rfcbot reviewed Thank you for a very clear and detailed writeup! |
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@rfcbot fcp resolve rustflags-profile-inconsistency |
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@rfcbot fcp resolved user-profile |
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🔔 This is now entering its final comment period, as per the review above. 🔔 |
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The final comment period, with a disposition to merge, as per the review above, is now complete. As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed. |
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Add a new Cargo configuration option,
build-std = "always|never", which will unconditionally rebuild standard library dependencies. The set of standard library dependencies can optionally be customised with a newbuild-std-cratesoption. It also describes how Cargo (or external tools) should build the standard library crates on stable (i.e., which flags to pass and features to enable).This proposal limits the ways the built standard library can be customised (such as by settings in the profile) and intends that the build standard library matches the prebuilt one (if available) as closely as possible.
This RFC is is part of the build-std project goal and a series of build-std RFCs:
build-std="always"(this RFC)build-std="compatible"(RFC not opened yet)build-std="match-profile"(RFC not opened yet)There is also a Zulip channel where you can ask questions about any of the build-std RFCs. This series of RFCs was drafted over many months with the help of stakeholders from many Rust project teams, we thank them for their help!
FCP
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