build: Add vllm arm precompiled wheel env variable

[ananthsub]

What does this PR do ?

Adding vllm arm precompiled wheel environment variable to build on ARM machines

Issues

Fixes #1952

Usage

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Additional Information

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Summary by CodeRabbit

• Chores
  • Enhanced build configuration to automatically detect and use the appropriate precompiled wheels based on system architecture, improving compatibility across different platforms.

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📝 Walkthrough

Walkthrough

The change modifies the VLLM wheel configuration script to conditionally select the appropriate precompiled wheel URL based on system architecture. If the system is aarch64, it uses the aarch64 wheel URL; otherwise, it defaults to the x86_64 wheel URL.

Changes

Cohort / File(s)	Summary
Build Script Architecture Support tools/build-custom-vllm.sh	Added architecture-aware conditional logic to select appropriate VLLM precompiled wheel URL based on system architecture (aarch64 vs. x86_64).

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

🚥 Pre-merge checks | ✅ 6

✅ Passed checks (6 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Linked Issues check	✅ Passed	The PR modifies build-custom-vllm.sh to add architecture-aware conditional logic for vllm wheel selection, directly addressing issue #1952's objective to enable vllm ARM precompiled wheel support.
Out of Scope Changes check	✅ Passed	The changes are limited to tools/build-custom-vllm.sh with architecture-aware wheel selection logic, remaining within the scope of adding ARM precompiled wheel support as defined in issue #1952.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Test Results For Major Changes	✅ Passed	Pull request contains minor changes limited to a build script with only +5/-1 lines modified, adding architecture-aware conditional logic without affecting core application logic or performance.
Title check	✅ Passed	The title accurately describes the main change: adding support for vllm ARM precompiled wheel via an environment variable, which matches the architecture-aware conditional logic implemented in the build script.

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Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

tools/build-custom-vllm.sh (1)

56-57: ⚠️ Potential issue | 🟡 Minor

Unset of UV_PROJECT_ENVIRONMENT will fail under set -eu if it's not already set.

Line 56 reads $UV_PROJECT_ENVIRONMENT without a default. If it's unset, set -u (from set -eou pipefail on line 16) will cause an immediate error. Similarly, line 93 re-exports it without guarding.

This is pre-existing, not introduced by this PR, but worth noting since it's on the execution path.

🛡️ Proposed fix

-OLD_UV_PROJECT_ENVIRONMENT=$UV_PROJECT_ENVIRONMENT
+OLD_UV_PROJECT_ENVIRONMENT="${UV_PROJECT_ENVIRONMENT:-}"

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@tools/build-custom-vllm.sh` around lines 56 - 57, The script reads and unsets
UV_PROJECT_ENVIRONMENT unsafely under set -u; change the assignment to use a
safe parameter expansion (e.g., assign OLD_UV_PROJECT_ENVIRONMENT using
${UV_PROJECT_ENVIRONMENT-} so it yields empty if unset) and when restoring,
guard the re-export/unset by checking the saved value (use [ -n
"${OLD_UV_PROJECT_ENVIRONMENT-}" ] to export UV_PROJECT_ENVIRONMENT back,
otherwise ensure it remains unset) so neither OLD_UV_PROJECT_ENVIRONMENT nor
re-exporting UV_PROJECT_ENVIRONMENT will trigger set -u failures.

🧹 Nitpick comments (1)

tools/build-custom-vllm.sh (1)

27-31: Consider allowing an environment variable override for VLLM_PRECOMPILED_WHEEL_LOCATION.

The PR objective mentions "introducing a configurable environment variable," but this code unconditionally overwrites any externally-set value. Wrapping in a guard would let users point to a custom wheel (e.g., a local mirror or a different version) without editing the script.

♻️ Proposed refactor

-if [[ "$(uname -m)" == "aarch64" ]]; then
-  VLLM_PRECOMPILED_WHEEL_LOCATION="https://github.com/vllm-project/vllm/releases/download/v0.13.0/vllm-0.13.0-cp38-abi3-manylinux_2_31_aarch64.whl"
-else
-  VLLM_PRECOMPILED_WHEEL_LOCATION="https://github.com/vllm-project/vllm/releases/download/v0.13.0/vllm-0.13.0-cp38-abi3-manylinux_2_31_x86_64.whl"
-fi
+if [[ -z "${VLLM_PRECOMPILED_WHEEL_LOCATION:-}" ]]; then
+  if [[ "$(uname -m)" == "aarch64" ]]; then
+    VLLM_PRECOMPILED_WHEEL_LOCATION="https://github.com/vllm-project/vllm/releases/download/v0.13.0/vllm-0.13.0-cp38-abi3-manylinux_2_31_aarch64.whl"
+  else
+    VLLM_PRECOMPILED_WHEEL_LOCATION="https://github.com/vllm-project/vllm/releases/download/v0.13.0/vllm-0.13.0-cp38-abi3-manylinux_2_31_x86_64.whl"
+  fi
+fi

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@tools/build-custom-vllm.sh` around lines 27 - 31, The script currently always
overwrites VLLM_PRECOMPILED_WHEEL_LOCATION in the arch-detection if/else block;
change it to respect an externally provided value by only assigning the default
wheel URL when VLLM_PRECOMPILED_WHEEL_LOCATION is empty/undefined (i.e., keep
the existing if [[ "$(uname -m)" == "aarch64" ]] { ... } else { ... } logic but
wrap or replace assignments so they only set a default when no env value
exists), referencing VLLM_PRECOMPILED_WHEEL_LOCATION and the arch-detection if
block so users can override with a custom URL.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Outside diff comments:
In `@tools/build-custom-vllm.sh`:
- Around line 56-57: The script reads and unsets UV_PROJECT_ENVIRONMENT unsafely
under set -u; change the assignment to use a safe parameter expansion (e.g.,
assign OLD_UV_PROJECT_ENVIRONMENT using ${UV_PROJECT_ENVIRONMENT-} so it yields
empty if unset) and when restoring, guard the re-export/unset by checking the
saved value (use [ -n "${OLD_UV_PROJECT_ENVIRONMENT-}" ] to export
UV_PROJECT_ENVIRONMENT back, otherwise ensure it remains unset) so neither
OLD_UV_PROJECT_ENVIRONMENT nor re-exporting UV_PROJECT_ENVIRONMENT will trigger
set -u failures.

---

Nitpick comments:
In `@tools/build-custom-vllm.sh`:
- Around line 27-31: The script currently always overwrites
VLLM_PRECOMPILED_WHEEL_LOCATION in the arch-detection if/else block; change it
to respect an externally provided value by only assigning the default wheel URL
when VLLM_PRECOMPILED_WHEEL_LOCATION is empty/undefined (i.e., keep the existing
if [[ "$(uname -m)" == "aarch64" ]] { ... } else { ... } logic but wrap or
replace assignments so they only set a default when no env value exists),
referencing VLLM_PRECOMPILED_WHEEL_LOCATION and the arch-detection if block so
users can override with a custom URL.