chore: fix intermittent timeouts in osx test runners (#6007)

* chore: workflow steps are no longer relevant

* fix: hoist build import to top of file

* test: use serial only for macosx and only in github actions

.github/workflows/workflow.yml

@@ -60,12 +60,6 @@ jobs:
             deno-version: 'v1.46.3'
       fail-fast: false
     steps:
-      # Increasing the maximum number of open files. See:
-      # https://github.com/actions/virtual-environments/issues/268
-      - name: Increase open file limit
-        run: sudo ulimit -Sn 65536
-        if: "${{ matrix.os == 'macos-14' }}"
-      - run: git config --global core.symlinks true
       # Sets an output parameter if this is a release PR
       - name: Check for release
         id: release-check

packages/build/ava.config.js

@@ -1,8 +1,14 @@
+import { platform } from 'node:os'
+import { env } from 'node:process'
+
 import baseConfig from '../../ava.base.js'
 
 const config = {
   ...baseConfig,
   files: ['tests/**/tests.{cjs,mjs,js}'],
+  // github action runners for osx have lower memory than windows/linux
+  // https://docs.github.com/en/actions/using-github-hosted-runners/using-github-hosted-runners/about-github-hosted-runners#standard-github-hosted-runners-for-public-repositories
+  serial: env.GITHUB_ACTIONS && platform() === 'darwin',
 }
 
 export default config

packages/testing/src/fixture.ts

@@ -4,6 +4,7 @@ import { normalize, delimiter } from 'path'
 import { env } from 'process'
 import { fileURLToPath } from 'url'
 
+import { default as build, startDev } from '@netlify/build'
 import test from 'ava'
 import cpy from 'cpy'
 import { execa, execaCommand } from 'execa'
@@ -194,7 +195,6 @@ export class Fixture {
 
   /** Runs @netlify/build main function programmatic with the provided flags  */
   async runBuildProgrammatic(): Promise<object> {
-    const { default: build } = await import('@netlify/build')
     return await build(this.getBuildFlags())
   }
 
@@ -204,7 +204,6 @@ export class Fixture {
   }
 
   async runWithBuildAndIntrospect() {
-    const { default: build } = await import('@netlify/build')
     const buildResult = await build(this.getBuildFlags())
     const output = [buildResult.logs?.stdout.join('\n'), buildResult.logs?.stderr.join('\n')]
       .filter(Boolean)
@@ -218,7 +217,6 @@ export class Fixture {
 
   // TODO: provide better typing if we know what's possible
   async runDev(devCommand: unknown): Promise<string> {
-    const { startDev } = await import('@netlify/build')
     const entryPoint = startDev.bind(null, devCommand)
     const { logs } = await entryPoint(this.getBuildFlags())
     return [logs.stdout.join('\n'), logs.stderr.join('\n')].filter(Boolean).join('\n\n')