[libcxx-commits] [libcxx] [libc++] Support build failures when running LNT benchmarks (PR #185234)

[Louis Dionne via libcxx-commits]

https://github.com/ldionne created https://github.com/llvm/llvm-project/pull/185234

It's rare but possible for the codebase not to build. When that happens, we should carry on and still submit an empty LNT report for that order, otherwise we'll get stuck thinking that order hasn't been benchmarked yet.

>From 49ff1c41aa93f4d960b1eca350502e021ac2697f Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne.2 at gmail.com>
Date: Sat, 7 Mar 2026 17:18:37 -0500
Subject: [PATCH] [libc++] Support build failures when running LNT benchmarks

It's rare but possible for the codebase not to build. When that happens,
we should carry on and still submit an empty LNT report for that order,
otherwise we'll get stuck thinking that order hasn't been benchmarked
yet.
---
 libcxx/utils/ci/lnt/run-benchmarks | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/libcxx/utils/ci/lnt/run-benchmarks b/libcxx/utils/ci/lnt/run-benchmarks
index 40c58eaff54e7..256871b6a8576 100755
--- a/libcxx/utils/ci/lnt/run-benchmarks
+++ b/libcxx/utils/ci/lnt/run-benchmarks
@@ -127,11 +127,12 @@ def main(argv):
         run([build_dir / '.venv/bin/pip', 'install', 'llvm-lnt'])
 
         logging.info(f'Building libc++ at commit {args.benchmark_commit}')
-        run([args.git_repo / 'libcxx/utils/build-at-commit',
+        build_cmd = [args.git_repo / 'libcxx/utils/build-at-commit',
                         '--git-repo', args.git_repo,
                         '--install-dir', build_dir / 'install',
                         '--commit', args.benchmark_commit,
-                        '--', '-DCMAKE_BUILD_TYPE=RelWithDebInfo', f'-DCMAKE_CXX_COMPILER={args.compiler}'])
+                        '--', '-DCMAKE_BUILD_TYPE=RelWithDebInfo', f'-DCMAKE_CXX_COMPILER={args.compiler}']
+        run(build_cmd, enforce_success=False) # if the build fails, carry on: we'll fail later and submit empty LNT results
 
         logging.info(f'Running benchmarks from {args.test_suite_commit} against libc++ {args.benchmark_commit}')
         cmd = [args.git_repo / 'libcxx/utils/test-at-commit',