Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

x.py: bootstrap keeps being recompiled #49215

Closed
SimonSapin opened this issue Mar 20, 2018 · 6 comments
Closed

x.py: bootstrap keeps being recompiled #49215

SimonSapin opened this issue Mar 20, 2018 · 6 comments
Labels
T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap)

Comments

@SimonSapin
Copy link
Contributor

Every x.py command seems to start like this for me:

./x.py something something
Updating only changed submodules
Submodules updated in 0.01 seconds
   Compiling libc v0.2.39
   Compiling dtoa v0.4.2
   Compiling lazy_static v0.2.11
   Compiling cfg-if v0.1.2
   Compiling num-traits v0.2.1
   Compiling unicode-xid v0.1.0
   Compiling serde v1.0.29
   Compiling getopts v0.2.15
   Compiling cc v1.0.6
   Compiling itoa v0.3.4
   Compiling proc-macro2 v0.2.3
   Compiling num_cpus v1.8.0
   Compiling time v0.1.39
   Compiling filetime v0.1.15
   Compiling build_helper v0.1.0 (file:///home/simon/rust3/src/build_helper)
   Compiling quote v0.4.2
   Compiling cmake v0.1.29
   Compiling syn v0.12.14
   Compiling serde_derive_internals v0.20.0
   Compiling serde_json v1.0.10
   Compiling toml v0.4.5
   Compiling serde_derive v1.0.29
   Compiling bootstrap v0.0.0 (file:///home/simon/rust3/src/bootstrap)
    Finished dev [unoptimized] target(s) in 12.12 secs
Building stage0 std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
[…]

Sometimes bootstrap and its dependencies are all rebuilt twice within the same x.py command!

12 seconds is not a lot compared to building two stages of rustc, but if it’s something that’s not too hard to fix it’s not negligible either.
@SimonSapin SimonSapin added A-build T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap) labels Mar 20, 2018
@petrochenkov
Copy link
Contributor

This is something relatively recent, maybe a few weeks or so.

@Mark-Simulacrum
Copy link
Member

@alexcrichton Do you by chance recall the RUST_LOG invocation to make cargo print why it's rebuilding bootstrap?

@Mark-Simulacrum
Copy link
Member

Found it: @petrochenkov or @SimonSapin, could you run with RUST_LOG=cargo::ops::cargo_rustc::fingerprint=info and report back with the results? You should see messages from cargo as to why it's recompiling unless we're unsetting RUST_LOG somewhere.

@SimonSapin
Copy link
Contributor Author

I think this only happens when I run ./x.py test without a specific test suite. bootstrap is built once (if necessary) to run the build system, then built once again after tidy runs:

[…]
* wrapping_iter_arith              lib      stable       1.14.0  
* wrapping_neg                     lib      stable       1.10.0  
* wrapping_ref                     lib      stable       1.14.0  
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for bootstrap v0.0.0 (file:///home/simon/rust/src/bootstrap): new (build_helper v0.1.0 (file:///home/simon/rust/src/build_helper)) != old (build_helper v0.1.0 (file:///home/simon/rust/src/build_helper))
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for build_helper v0.1.0 (file:///home/simon/rust/src/build_helper): RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for filetime v0.1.15: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for cfg-if v0.1.2: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for libc v0.2.39: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for lazy_static v0.2.11: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for getopts v0.2.15: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for serde v1.0.29: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for cmake v0.1.29: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for cc v1.0.6: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for toml v0.4.5: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for num_cpus v1.8.0: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for serde_json v1.0.10: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for itoa v0.3.4: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for dtoa v0.4.2: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for num-traits v0.2.1: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for time v0.1.39: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for serde_derive v1.0.29: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for serde_derive_internals v0.20.0: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for proc-macro2 v0.2.3: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for unicode-xid v0.1.0: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for syn v0.12.14: RUSTFLAGS has changed
 INFO 2018-03-23T10:13:44Z: cargo::ops::cargo_rustc::fingerprint: fingerprint error for quote v0.4.2: RUSTFLAGS has changed
   Compiling cc v1.0.6
   Compiling getopts v0.2.15
   Compiling lazy_static v0.2.11
   Compiling serde v1.0.29
   Compiling libc v0.2.39
   Compiling dtoa v0.4.2
   Compiling itoa v0.3.4
   Compiling unicode-xid v0.1.0
   Compiling num-traits v0.2.1
   Compiling cfg-if v0.1.2
   Compiling proc-macro2 v0.2.3
   Compiling time v0.1.39
   Compiling num_cpus v1.8.0
   Compiling filetime v0.1.15
   Compiling build_helper v0.1.0 (file:///home/simon/rust/src/build_helper)
   Compiling cmake v0.1.29
   Compiling quote v0.4.2
   Compiling syn v0.12.14
   Compiling serde_derive_internals v0.20.0
   Compiling serde_derive v1.0.29
   Compiling toml v0.4.5
   Compiling serde_json v1.0.10
   Compiling bootstrap v0.0.0 (file:///home/simon/rust/src/bootstrap)
    Finished dev [unoptimized] target(s) in 8.39 secs
     Running /home/simon/rust/build/bootstrap/debug/deps/bootstrap-39586fcf3cf86d31

running 0 tests

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

Building stage0 test artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
[…]

(It looks like this second build is done in order to run a grand total of… zero tests.)

As the log say (thanks for the invocation @Mark-Simulacrum), RUSTFLAGS has changed.

cat /proc/$(pgrep cargo)/environ | tr '\0' '\n' | grep RUSTFLAGS

This shows RUSTFLAGS=-Cdebuginfo=2 during the inital bootstrap build and nothing during the testing build. env["RUSTFLAGS"] = "-Cdebuginfo=2" is set in src/bootstrap/bootstrap.py.

@Mark-Simulacrum
Copy link
Member

We should just set those rustflags during the second build probably... If someone wants to make a PR, it should be in src/bootstrap/test.rs, under impl Step for Bootstrap.

SimonSapin added a commit to SimonSapin/rust that referenced this issue Mar 23, 2018
@SimonSapin
Use the same RUSTFLAGS for building and testing bootstrap
e993e62 
Fixes rust-lang#49215
@SimonSapin SimonSapin mentioned this issue Mar 23, 2018
Merged
@SimonSapin
Copy link
Contributor Author

#49311

alexcrichton added a commit to alexcrichton/rust that referenced this issue Mar 23, 2018
@alexcrichton
Rollup merge of rust-lang#49311 - SimonSapin:bootstrap-vs-rustflags-t…
0615e6b 
…he-return, r=Mark-Simulacrum

Use the same RUSTFLAGS for building and testing `bootstrap`

This avoids recompiling the whole dependency graph twice for every `./x.py test` run.

Fixes rust-lang#49215
bors added a commit that referenced this issue Mar 23, 2018
@bors
Auto merge of #49311 - SimonSapin:bootstrap-vs-rustflags-the-return, …
4be5d36 
…r=Mark-Simulacrum

Use the same RUSTFLAGS for building and testing `bootstrap`

This avoids recompiling the whole dependency graph twice for every `./x.py test` run.

Fixes #49215
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap)
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
3 participants
@SimonSapin @Mark-Simulacrum @petrochenkov