Remove unused cusolver/curand deps from libcuopt

[ramakrishnap-nv]

Neither cusolver nor curand is referenced anywhere in cpp/src, and no RAFT header cuOpt includes touches either library. Verified with a full local build: nm -D --undefined-only on the resulting libcuopt.so shows zero cusolver/curand symbols among its 762 undefined dynamic symbols.

libcusolver-dev/libcurand-dev removed from dependencies.yaml (conda environments regenerated). libcurand-dev and its ignore_run_exports entry removed from recipe.yaml — cusolver was never explicitly declared there, only inherited via libraft-headers.

curand was added deliberately in the past (not just inherited), despite the same zero-usage finding — see git blame on the removed CUDA::curand line (9f241a19, around when the barrier method moved to cuDSS for sparse Cholesky/LDLT) for context worth a second look.

Out of scope: the cuda_wheels pip/wheel install path (separate distribution channel, untested here), and switching libraft-headers → libraft-headers-only (bigger change, needs its own conda-build validation).

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[ramakrishnap-nv]

/ok to test aaae5a6

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CI Test Summary

✅ All 31 test job(s) passed.

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No actionable comments were generated in the recent review. 🎉

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📥 Commits

Reviewing files that changed from the base of the PR and between 269fb4c and aaae5a6.

📒 Files selected for processing (7)

• conda/environments/all_cuda-129_arch-aarch64.yaml
• conda/environments/all_cuda-129_arch-x86_64.yaml
• conda/environments/all_cuda-133_arch-aarch64.yaml
• conda/environments/all_cuda-133_arch-x86_64.yaml
• conda/recipes/libcuopt/recipe.yaml
• cpp/CMakeLists.txt
• dependencies.yaml

💤 Files with no reviewable changes (7)

• conda/environments/all_cuda-129_arch-aarch64.yaml
• conda/environments/all_cuda-133_arch-aarch64.yaml
• dependencies.yaml
• conda/recipes/libcuopt/recipe.yaml
• conda/environments/all_cuda-133_arch-x86_64.yaml
• cpp/CMakeLists.txt
• conda/environments/all_cuda-129_arch-x86_64.yaml

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📝 Walkthrough

Walkthrough

The change removes libcurand and libcusolver dependencies from CUDA Conda environments, the shared dependency group, cuOpt recipe metadata, and private CMake linkage.

Changes

CUDA dependency cleanup

Layer / File(s)	Summary
CUDA package declarations dependencies.yaml, conda/environments/all_cuda-129_*.yaml, conda/environments/all_cuda-133_*.yaml	The CUDA dependency group and CUDA 12.9/13.3 environment definitions no longer include libcurand-dev or libcusolver-dev.
cuOpt build and packaging alignment cpp/CMakeLists.txt, conda/recipes/libcuopt/recipe.yaml	Private CMake linkage no longer includes CUDA::curand or CUDA::cusolver. The cuOpt recipe no longer declares libcurand-dev as a host requirement or ignores libcurand run exports.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to aaae5

This change removes unused cuSolver and cuRAND dependencies from the build and package environments without changing library behavior; no actionable merge-blocking risk remains after normal checks and review.

Suggested reviewers: tmckayus, jakirkham

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main change: removing unused cuSolver and cuRAND dependencies from libcuOpt.
Description check	✅ Passed	The description directly explains the dependency removals, supporting build verification, and the stated out-of-scope areas.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Docstring Coverage

Explanation

No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0 files.

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch test/drop-unused-cusolver-link

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[ramakrishnap-nv]

/merge