[devmotion]

Adds a QATests test set that runs Aqua, ExplicitImports and JET.

Changes

• Explicit imports in src/ReverseDiff.jl, and fixes for the other ExplicitImports findings: Base.inv instead of LinearAlgebra.inv, no self-qualified accesses, a stale BroadcastStyle import. @grad_from_chainrules now interpolates ReverseDiff and ChainRulesCore into the code it generates, like @grad already does.
• holdsperturbations in src/derivatives/broadcast.jl asserts ::Bool on the result of all. For an abstract Tuple, all infers as Union{Missing, Bool}, so JET reported a non-boolean condition in copy(::Broadcasted{<:TrackedStyle}) for every jacobian of a broadcasting function.

Checks marked broken

• Aqua.test_ambiguities: methods generated with @eval clash with Base and LinearAlgebra: 551 ambiguities on Julia 1.12, 562 on 1.13, 1809 on 1.10.
• JET reports every entry point that differentiates a function with a scalar output. The analysis reaches pull_value!(::TrackedReal{V, D, Nothing}) in src/tracked.jl, where t.origin is non-nothing only because of the run-time check hasorigin(t). @test_opt on uncompiled tapes is also broken, because they dispatch on AbstractInstruction at run time.

Version notes

• The ExplicitImports publicness checks only run on Julia >= 1.11. Julia 1.10 has no public keyword, so it reports names such as Base.tail that later versions mark public.
• JET >= 0.11.4 requires Julia >= 1.12, so no single version resolves on all Julia versions in the CI matrix. The compat entry therefore also allows JET 0.9.18, and the checks only run if JET_AVAILABLE is defined and true. JET is added to the skip list of the downgrade job, which would otherwise pin it to 0.9.18 on Julia >= 1.12, where it does not precompile.

Testing

QATests passes locally on Julia 1.12.7 and 1.13.1 (run directly) and on 1.10.12 (via Pkg.test(; test_args=["QATests"])). The rest of the suite and the downgrade job were not run locally.

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 94.11765% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 94.29%. Comparing base (51cda83) to head (67959be).

Files with missing lines	Patch %	Lines
src/derivatives/linalg/arithmetic.jl	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #299   +/-   ##
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  Coverage   94.29%   94.29%           
=======================================
  Files          19       19           
  Lines        1699     1699           
=======================================
  Hits         1602     1602           
  Misses         97       97           

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