rustc 1.25.0 panics with "Cannot allocate memory" while building Firefox 59 for Manjaro Linux i686 within Docker build container

[jonathonf]

Summary

While trying to build Firefox 59.0.2 for i686 under a Manjaro Linux (Arch-like) Docker-based build container, rustc panics with "Cannot allocate memory" while compiling the gkrust crate.

I'm reporting because the backtrace asked me to. :)

Details

On first look this would appear to be rustc trying to allocate more than ~3GB RAM during the LTO step as seen https://bugzilla.mozilla.org/show_bug.cgi?id=1417268#c13, and a similar thing last occurred with rustc 1.22 (https://bbs.archlinux32.org/viewtopic.php?id=643).

Monitoring RAM usage during the failing compilation step appears to show it remaining fairly constant at ~1.3GB RES for a "long" period (~50% time before failure), jumping to ~1.5GB RES, then jumping again to 1.7GB and 2.0GB (~80% TBF), before finally (~95% TBF) rapidly increasing in ~100MB steps and panicking somewhere around ~3GB RES.

I am able to successfully build 64-bit Firefox 59.0.2, as well as both 32- and 64-bit Firefox ESR 52.7.3 with the same build container setup, so it looks to be something specific between i686 rustc and FF 59's use of the gkrust crate.

I have not set any resource limits for Docker.

Steps which might reproduce

git clone https://github.com/jonathonf/manjaro-32-build.git
mkdir firefox && cd $_
curl -L -f "https://git.archlinux.org/svntogit/packages.git/snapshot/packages/firefox.tar.gz" -o - | bsdtar --strip-components 3 --include="*/firefox/trunk/" -xvf -
../manjaro-32-build/run.sh

Failing command with flags

/usr/bin/rustc --crate-name gkrust lib.rs --color always --crate-type staticlib --emit=dep-info,link -C opt-level=2 -C panic=abort -C lto --cfg feature="bindgen" --cfg feature="cubeb-remoting" --cfg feature="cubeb_pulse_rust" --cfg feature="gkrust-shared" --cfg feature="no-static-ideograph-encoder-tables" --cfg feature="servo" --cfg feature="simd-accel" -C metadata=651646389c08113e -C extra-filename=-651646389c08113e --out-dir /build/src/mozilla-unified/obj-i686-pc-linux-gnu/toolkit/library/i686-unknown-linux-gnu/release/deps --target i686-unknown-linux-gnu -C linker=/build/src/mozilla-unified/build/cargo-linker -L dependency=/build/src/mozilla-unified/obj-i686-pc-linux-gnu/toolkit/library/i686-unknown-linux-gnu/release/deps -L dependency=/build/src/mozilla-unified/obj-i686-pc-linux-gnu/toolkit/library/release/deps --extern gkrust_shared=/build/src/mozilla-unified/obj-i686-pc-linux-gnu/toolkit/library/i686-unknown-linux-gnu/release/deps/libgkrust_shared-f2bb0c738944c0f6.rlib -C opt-level=2 -C debuginfo=2

Backtrace

 8:40.67    Compiling gkrust v0.1.0 (file:///build/src/mozilla-unified/toolkit/library/rust)
35:17.52 thread 'rustc' panicked at 'called `Result::unwrap()` on an `Err` value: Custom { kind: Other, error: StringError("Cannot allocate memory") }', libcore/result.rs:945:5
35:17.53 stack backtrace:
35:17.71    0: 0xf747766a - rust_metadata_std_ae049937c58eac2695c432bfa6d5d39f
35:17.71    1: 0xf746f0fb - rust_metadata_std_ae049937c58eac2695c432bfa6d5d39f
35:17.71    2: 0xf7474224 - rust_metadata_std_ae049937c58eac2695c432bfa6d5d39f
35:17.71    3: 0xf7473f4f - rust_metadata_std_ae049937c58eac2695c432bfa6d5d39f
35:17.71    4: 0xf74746a1 - std::panicking::rust_panic_with_hook::hb8beb8efb6b91903
35:17.71    5: 0xf7474515 - rust_metadata_std_ae049937c58eac2695c432bfa6d5d39f
35:17.71    6: 0xf7474496 - std::panicking::begin_panic_fmt::he4dfe7a67e7c0076
35:17.71    7: 0xf74743fb - rust_begin_unwind
35:17.71    8: 0xf74e226e - core::panicking::panic_fmt::he2c3b98e9730a002
35:17.71    9: 0xf04c7497 - <unknown>
35:17.71   10: 0xf04f5667 - <unknown>
35:17.71   11: 0xf04f4320 - <unknown>
35:17.71   12: 0xf0593809 - <unknown>
35:17.71   13: 0xf05912b1 - <rustc_trans::LlvmTransCrate as rustc_trans_utils::trans_crate::TransCrate>::join_trans_and_link::hd108c8a9e5d89c4d
35:17.71   14: 0xf762d843 - rustc_driver::driver::compile_input::hd9c20dd67b35c276
35:17.71   15: 0xf764a9b5 - rustc_driver::run_compiler::h2b965134b6c46ea8
35:17.71   16: 0xf756d933 - rust_metadata_rustc_driver_9af17ad1a24b9c2356fb6a6c6e5db9d5
35:17.71   17: 0xf748bdd2 - __rust_maybe_catch_panic
35:17.71   18: 0xf75a7b93 - <unknown>
35:17.71   19: 0xf7482bfa - rust_metadata_std_ae049937c58eac2695c432bfa6d5d39f
35:17.71   20: 0xf5854e55 - start_thread
35:17.71   21: 0xf73366b5 - __GI___clone
35:17.71   22:        0x0 - <unknown>
35:17.75 
35:17.75 error: internal compiler error: unexpected panic
35:17.75 
35:17.75 note: the compiler unexpectedly panicked. this is a bug.
35:17.75 
35:17.75 note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
35:17.75 
35:17.75 note: rustc 1.25.0 running on i686-unknown-linux-gnu
35:17.75 
35:17.94 error: Could not compile `gkrust`.
35:17.94 
35:17.94 To learn more, run the command again with --verbose.
35:17.94 make[4]: *** [/build/src/mozilla-unified/config/rules.mk:972: force-cargo-library-build] Error 101
35:17.94 make[3]: *** [/build/src/mozilla-unified/config/recurse.mk:73: toolkit/library/rust/target] Error 2
35:17.94 make[2]: *** [/build/src/mozilla-unified/config/recurse.mk:33: compile] Error 2
35:17.94 make[1]: *** [/build/src/mozilla-unified/config/rules.mk:434: default] Error 2
35:17.94 make: *** [client.mk:168: build] Error 2
35:17.97 0 compiler warnings present.
35:18.04 Failed to parse ccache stats output: stats zero time                     Thu Apr  5 15:52:33 2018
35:18.04 Notification center failed: Install notify-send (usually part of the libnotify package) to get a notification when the build finishes.

rustc --version --verbose

rustc 1.25.0
binary: rustc
commit-hash: unknown
commit-date: unknown
host: i686-unknown-linux-gnu
release: 1.25.0
LLVM version: 6.0

Packaging files

rustc: https://www.archlinux.org/packages/community/x86_64/rust/
firefox: https://www.archlinux.org/packages/extra/x86_64/firefox/

[cuviper]

I saw similar issues on armv7 in #45854, first for rustc itself and later reported with Firefox. In Fedora, I've now disabled rust debuginfo on all 32-bit platforms as a workaround. :-/

[jonathonf]

export RUSTFLAGS="-Cdebuginfo=0" works wonders. Build succeeded and it cut compilation time!

[nikomatsakis]

triage: P-medium

Discussed in the @rust-lang/compiler meeting -- is it possible to do a run with massif (in 64-bit, presumably), to try and see where the memory usage has gone? In general, we feel like it's probably best to just try to reduce memory usage generally, but if there's a specific change it might be good to know.

[jonathonf]

It's looking like getting this specific step to run under valgrind might be tricky; I'll keep looking though. Alternatively, I'll see whether I can replicate something similar with a more minimal use of the gkrust crate.

[steveklabnik]

Visiting for triage. A lot has changed, are you still seeing this? any chance of a smaller reproduction?

[Mark-Simulacrum]

Going to go ahead and close since we don't have a minimal reproduction and it's been years - including changes to gkrust and such.