Build failure: deno

[feathecutie]

Nixpkgs version

• Unstable (25.11)

Steps to reproduce

nix build github:NixOS/nixpkgs/nixos-unstable#deno

Can Hydra reproduce this build failure?

Yes, Hydra can reproduce this build failure.

Link to Hydra build job

https://hydra.nixos.org/build/300144659#tabs-summary

Relevant log output

Running unittests lib.rs (target/x86_64-unknown-linux-gnu/release/deps/deno_node-0f42e7b7460cbef7)

running 11 tests
test ops::blocklist::tests::test_add_address ... ok
test ops::blocklist::tests::test_add_subnet ... ok
test ops::blocklist::tests::test_add_range ... ok
test ops::blocklist::tests::test_check ... ok
test ops::crypto::primes::tests::test_composite ... ok
test ops::zlib::tests::zlib_start_write ... ok
test ops::crypto::primes::tests::oeis_a014233 ... ok
test ops::os::cpus::tests::test_cpu_info ... ok
error: test failed, to rerun pass `-p deno_node --lib`

Caused by:
  process didn't exit successfully: `/build/source/target/x86_64-unknown-linux-gnu/release/deps/deno_node-0f42e7b7460cbef7 '--skip=check::ts_no_recheck_on_redirect' '--skip=js_unit_tests::quic_test' '--skip=js_unit_tests::net_test' '--skip=node_unit_tests::http_test' '--skip=node_unit_tests::http2_test' '--skip=node_unit_tests::net_test' '--skip=node_unit_tests::tls_test' '--skip=npm::lock_file_lock_write' '--skip=js_unit_tests::webgpu_test' '--skip=js_unit_tests::jupyter_test' '--skip=specs::permission::proc_self_fd' '--skip=init::init_subcommand_serve' '--skip=repl::pty_complete_imports_no_panic_empty_specifier'` (signal: 11, SIGSEGV: invalid memory reference)

Additional context

No response

System metadata

• system: "x86_64-linux"
• host os: Linux 6.15.2, NixOS, 25.11 (Xantusia), 25.11.20250613.ee930f9
• multi-user?: yes
• sandbox: yes
• version: nix-env (Lix, like Nix) 2.93.0
• channels(root): ""
• nixpkgs: /nix/store/xnr2xjs0clkhlhqfc3vqcmhnnwdk3c5p-source

Notify maintainers

@06kellyjac @ofalvai

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[limwa]

Related to #384838.

[limwa]

It appears one or more of the tests are flaky. After 2 tries, I was able to build the derivation locally. Unfortunately, I don't think Hydra will try to rerun the build because the derivation itself hasn't changed.

[limwa]

After a few hours of debugging, I found the flaky test is ops::ipc::impl_::tests::ipc_serialization.

[ofalvai]

FYI this is being addressed in #416177.

@limwa are you sure your failure is caused by that one specific test and not the test runner itself crashing? Because my experience is the latter, it crashes with SIGSEGV on x86_64-linux only. And SIGSEGV is also present in the log snippet you posted.

[limwa]

@ofalvai I don't know for certain if it's the test or the test runner causing the crashes.

From my empirical testing, I do know that skipping that test reduces the crash rate from ~50% to 0%, in Deno 2.3.5, based on 500 executions. In Deno 2.3.6, the test ops::tests::tcp_set_keepalive also needs to be skipped to completely eliminate SIGSEGV crashes.

EDIT: the coredump suggests that these tests might not be the true causes of the SIGSEGV crashes

[nwayve]

Is this related to the unusually long buildPhase? In a dev project's flake, I ran nix flake update and then nix develop and it just takes an insanely long time for the Deno buildPhase. Example:

[1/0/2 built, 0.0 MiB DL] building deno-2.3.5 (buildPhase): Compiling darling_macro v0.20.10

It sits there but is rotating through various "Compiling {x}". I haven't even gotten to a failed test yet. Been waiting for 20+ minutes for this buildPhase to complete (and it's still going).

[limwa]

Yes, it is. Because the build failed in hydra, the resulting store outputs were not uploaded to cache.nixos.org and, as such, nix will try to build them locally instead of just downloading them.

[limwa]

Can someone please close this issue? The fix for the build failure has already been merged to master.

https://nixpk.gs/pr-tracker.html?pr=416177

[06kellyjac]

it just takes an insanely long time for the Deno buildPhase

deno naturally has a long build time because it's a big project & crucially it has a lot of linking to do which is pretty slow. Compiling doesn't take too long on my 32 thread machine but then it's stuck on 1-2 threads linking for like 10 minutes+

We could switch out the linker but it's best to follow upstream & most users will get a copy from the cache when things are working correctly.