Bootstrapping from previous releases #29555
Comments
|
@alexcrichton's build system rewrite eliminates snapshots, but that may take a long time yet to land. |
alexcrichton
added a commit
to alexcrichton/rust
that referenced
this issue
Apr 19, 2016
This commit removes all infrastructure from the repository for our so-called snapshots to instead bootstrap the compiler from stable releases. Bootstrapping from a previously stable release is a long-desired feature of distros because they're not fans of downloading binary stage0 blobs from us. Additionally, this makes our own CI easier as we can decommission all of the snapshot builders and start having a regular cadence to when we update the stage0 compiler. A new `src/etc/get-stage0.py` script was added which shares some code with `src/bootstrap/bootstrap.py` to read a new file, `src/stage0.txt`, which lists the current stage0 compiler as well as cargo that we bootstrap from. This script will download the relevant `rustc` package an unpack it into `$target/stage0` as we do today. One problem of bootstrapping from stable releases is that we're not able to compile unstable code (e.g. all the `#![feature]` directives in libcore/libstd). To overcome this we employ two strategies: * The bootstrap key of the previous compiler is hardcoded into `src/stage0.txt` (enabled as a result of rust-lang#32731) and exported by the build system. This enables nightly features in the compiler we download. * The standard library and compiler are pinned to a specific stage0, which doesn't change, so we're guaranteed that we'll continue compiling as we start from a known fixed source. The process for making a release will also need to be tweaked now to continue to cadence of bootstrapping from the previous release. This process looks like: 1. Merge `beta` to `stable` 2. Produce a new stable compiler. 3. Change `master` to bootstrap from this new stable compiler. 4. Merge `master` to `beta` 5. Produce a new beta compiler 6. Change `master` to bootstrap from this new beta compiler. Step 3 above should involve very few changes as `master` was previously bootstrapping from `beta` which is the same as `stable` at that point in time. Step 6, however, is where we benefit from removing lots of `#[cfg(stage0)]` and get to use new features. This also shouldn't slow the release too much as steps 1-5 requires little work other than waiting and step 6 just needs to happen at some point during a release cycle, it's not time sensitive. Closes rust-lang#29555 Closes rust-lang#29557
bors
added a commit
that referenced
this issue
Apr 20, 2016
mk: Bootstrap from stable instead of snapshots This commit removes all infrastructure from the repository for our so-called snapshots to instead bootstrap the compiler from stable releases. Bootstrapping from a previously stable release is a long-desired feature of distros because they're not fans of downloading binary stage0 blobs from us. Additionally, this makes our own CI easier as we can decommission all of the snapshot builders and start having a regular cadence to when we update the stage0 compiler. A new `src/etc/get-stage0.py` script was added which shares some code with `src/bootstrap/bootstrap.py` to read a new file, `src/stage0.txt`, which lists the current stage0 compiler as well as cargo that we bootstrap from. This script will download the relevant `rustc` package an unpack it into `$target/stage0` as we do today. One problem of bootstrapping from stable releases is that we're not able to compile unstable code (e.g. all the `#![feature]` directives in libcore/libstd). To overcome this we employ two strategies: * The bootstrap key of the previous compiler is hardcoded into `src/stage0.txt` (enabled as a result of #32731) and exported by the build system. This enables nightly features in the compiler we download. * The standard library and compiler are pinned to a specific stage0, which doesn't change, so we're guaranteed that we'll continue compiling as we start from a known fixed source. The process for making a release will also need to be tweaked now to continue to cadence of bootstrapping from the previous release. This process looks like: 1. Merge `beta` to `stable` 2. Produce a new stable compiler. 3. Change `master` to bootstrap from this new stable compiler. 4. Merge `master` to `beta` 5. Produce a new beta compiler 6. Change `master` to bootstrap from this new beta compiler. Step 3 above should involve very few changes as `master` was previously bootstrapping from `beta` which is the same as `stable` at that point in time. Step 6, however, is where we benefit from removing lots of `#[cfg(stage0)]` and get to use new features. This also shouldn't slow the release too much as steps 1-5 requires little work other than waiting and step 6 just needs to happen at some point during a release cycle, it's not time sensitive. Closes #29555 Closes #29557
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Bootstrapping from arbitrary commits is too difficult for downstream distributors that want to bootstrap from their own binaries.
We'll retire the current snapshot system, and bootstrap off of the previous stable compiler. This means that upstream will need to wait six weeks between making changes that are incompatible with the bootstrap compiler. At present, the snapshot compiler is regenerated rarely, so this is expected to be ok.
I expect that smaller distros will not be able to keep up with our six week release schedule, but a simple script should allow them to catch up on the bootstrap by rebuilding the intermediate compilers.
We'll set up CI to ensure that the distro scenario of locally providing the previous compiler works for each release.
Make sure to consider what happens for stable point releases, which we have never done. We probably need to guarantee that all point releases from series
Ncan bootstrap all point releases from seriesN+1.Details TBD.
re https://internals.rust-lang.org/t/perfecting-rust-packaging-the-plan/2767
The text was updated successfully, but these errors were encountered: