Who contributed to Google on July 5, 2026?

2 developers shipped this update, including mattjj and copybara-service[bot].

What were the notable Google updates?

[vjp3][mutable-arrays] fix scan transpose bugs with refs, [JAX] Enable CHLO lowering for cumulative sums on GPU again, and Update XLA dependency to use revision http://github.com/openxla/xla/commit/42d2e6ac6c715184ab7a64855f5162f03c561b29.

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Jul 5, 2026

$ the-wire · showcase

JAX FIXES CRITICAL SCAN TRANSPOSE BUG THAT BROKE REF ACCUMULATORS

By RepoJournal · Filed 06:02 UTC on July 5, 2026 · About Google · Composed from the cited sources · methodology

2 people shipped this

mattjj @mattjj 1 cited

copybara-service[bot] @copybara-service[bot] 1 cited

A foundational bug in JAX's scan transpose logic is fixed after the code assumed accumulators would follow a neat type-sorted pattern they never actually did.

The scan transpose implementation was making a dangerous assumption about how ref accumulators would be arranged in memory [1]. The code expected them to be sorted and contiguous by type, but real-world usage scattered them arbitrarily across the accumulator space. This created silent correctness issues that the new canonicalization logic now handles properly, complete with systematic test coverage to prevent regression [1]. In parallel, JAX is restoring cumulative sum performance on GPU by re-enabling CHLO lowering after a recent disable [2]. XLA dependencies were also bumped to the latest revision to align with upstream improvements [3].

Action items

→ Pull the latest JAX commit with ref accumulator fix [ref:1] if you use scan with mutable refs google/jax [immediate]
→ Test cumulative sum operations on GPU to verify performance is back to baseline google/jax [monitor]

References

[1] [vjp3][mutable-arrays] fix scan transpose bugs with refs ↗ google/jax
[2] [JAX] Enable CHLO lowering for cumulative sums on GPU again. ↗ google/jax
[3] Update XLA dependency to use revision http://github.com/openxla/xla/commit/42d2e6ac6c715184ab7a64855f5162f03c561b29 ↗ google/jax

$ ls google/reviews/ # the step-back reads

the week in review JAX drops legacy IFRT device APIs, google-auth adds 3.15 the month in review JAX free-threading push reshapes 0.11.2 and 0.12 cleanup

Full archive → Weekly reviews →

Quick answers

What shipped in Google on July 5, 2026?: A foundational bug in JAX's scan transpose logic is fixed after the code assumed accumulators would follow a neat type-sorted pattern they never actually did. In total, 3 commits and 2 pull requests landed.
Who contributed to Google on July 5, 2026?: 2 developers shipped this update, including mattjj and copybara-service[bot].
What were the notable Google updates?: [vjp3][mutable-arrays] fix scan transpose bugs with refs, [JAX] Enable CHLO lowering for cumulative sums on GPU again, and Update XLA dependency to use revision http://github.com/openxla/xla/commit/42d2e6ac6c715184ab7a64855f5162f03c561b29.

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$ log Google --recent

2026-10-04 JAX pins OpenXLA revision, disables overlap_test against older libtpu 5 shipped 2026-10-03 JAX adds type-2 and type-3 Hermitian eigensolves, lexsort batching cuts unique compile time 69 shipped 2026-10-02 JAX hijax flags read at call time, Spanner stops deleting multiplexed sessions 112 shipped 2026-10-01 Vertex AI client timeout fix, Compute v1 API regenerated 87 shipped

$ log --all # elsewhere on the wire

@vuejs 2026-10-04 Vue language tools stop calling registerHooks on buggy Node builds @openclaw 2026-10-04 OpenClaw's deslop sweep removes 1,000+ production lines

$ ls showcases/

$ init your-desk

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