docs: add developer's guide for running CodeBuild locally

[scottschreckengaust]

Summary

• Adds docs/DEVELOPERS_GUIDE.md with instructions for running CodeBuild locally using the local agent
• Documents all codebuild_build.sh flags including -b for buildspec overrides, -c for AWS credentials, and -e for environment variables
• Adds .codebuild/** to .gitignore for local build artifacts

Test plan

• Verify markdown renders correctly on GitHub
• Confirm codebuild_build.sh commands work locally with -b flag

🤖 Generated with Claude Code

[scottschreckengaust]

An alternative is including instructions in this GitHub Wiki. This is viable, but will not be pulled down while developing and could be missed.

https://github.com/awslabs/aidlc-workflows/wiki

I would argue that the Wiki should be disabled.

[harmjeff]

I have reviewed it and run it locally. Looks good

[raj-jain-aws]

Ran this. Got output but not sure how to interpret it. What should we be looking for?

agent-1  | 
agent-1  | [Container] 2026/03/10 00:30:25.798527 Phase complete: BUILD State: SUCCEEDED
agent-1  | [Container] 2026/03/10 00:30:25.798597 Phase context status code:  Message: 
agent-1  | [Container] 2026/03/10 00:30:25.813077 Entering phase POST_BUILD
agent-1  | [Container] 2026/03/10 00:30:25.822893 Running command echo "post_build ${TEST_ONE}" | tee --append ./codebuild.out
agent-1  | post_build 1
agent-1  | 
agent-1  | [Container] 2026/03/10 00:30:25.864239 Running command echo "Build completed with status $CODEBUILD_BUILD_SUCCEEDING"
agent-1  | Build completed with status 1
agent-1  | 
agent-1  | [Container] 2026/03/10 00:30:25.898186 Running command cat ./codebuild.out
agent-1  | install 1
agent-1  | pre_build 1
agent-1  | build 1
agent-1  | post_build 1
agent-1  | 
agent-1  | [Container] 2026/03/10 00:30:25.921089 Phase complete: POST_BUILD State: SUCCEEDED
agent-1  | [Container] 2026/03/10 00:30:25.921136 Phase context status code:  Message: 
agent-1  | [Container] 2026/03/10 00:30:25.946802 Expanding base directory path: .
agent-1  | [Container] 2026/03/10 00:30:25.951568 Assembling file list
agent-1  | [Container] 2026/03/10 00:30:25.951596 Expanding .
agent-1  | [Container] 2026/03/10 00:30:25.958629 Expanding file paths for base directory .
agent-1  | [Container] 2026/03/10 00:30:25.958656 Assembling file list
agent-1  | [Container] 2026/03/10 00:30:25.958659 Expanding **/codebuild.out
agent-1  | [Container] 2026/03/10 00:30:25.964005 Found 1 file(s)
agent-1  | [Container] 2026/03/10 00:30:25.975225 Preparing to copy secondary artifacts
agent-1  | [Container] 2026/03/10 00:30:25.975279 No secondary artifacts defined in buildspec
agent-1  | [Container] 2026/03/10 00:30:25.978919 Phase complete: UPLOAD_ARTIFACTS State: SUCCEEDED
agent-1  | [Container] 2026/03/10 00:30:25.978975 Phase context status code:  Message: 
Aborting on container exit...
agent-1 exited with code 0
[+] Stopping 2/0
 ✔ Container agent-resources-build-1  Stopped0.0s 
 ✔ Container agent-resources-agent-1  Stopped0.0s 

[scottschreckengaust]

Ran this. Got output but not sure how to interpret it. What should we be looking for?

This shows that you have successfully run a local AWS CodeBuild. The four "phases" of the workflow outline the commands that will be run in order (install, pre_build, build, and post_build)

I updated the section of the build specification override to install the GitHub CLI, gh, set if the run is in a "release" (tagged)/"pre-release" (the default main branch)/"pre-merge" (any other non-default branch).