fix: update Homebrew formula to use PyYAML 6.0.3 and automate versioning

[mdvanes]

Hi,

I've been investigating a Homebrew install failure that affects anyone who tries brew tap eschaar/vstack && brew install vstack today. Here's the full picture and what needs to change on your end.

What's broken and why

brew install vstack currently fails with:

The root cause is in Formula/vstack.rb in this repo (eschaar/homebrew-vstack). The pyyaml resource block was committed with empty url and sha256 values:

Homebrew cannot install a resource with no URL, so the install fails immediately.

This happened because the automated dispatch from vstack/publish.yml was never enabled (HOMEBREW_TAP_ENABLED was "false"), so the formula was manually seeded but with placeholder values that were never filled in.

Fix 1 — immediate: patch Formula/vstack.rb (one manual commit to this repo)

Replace the pyyaml resource block with the correct PyYAML 6.0.3 values (latest stable, satisfies the >=6.0 constraint in vstack's pyproject.toml):

This is the only change needed to unblock installs today.

Fix 2 — structural: replace the formula-update.yml update step (one commit to this repo)

There's a second bug that will cause the same problem again on the next automated release. The current formula-update.yml uses sed patterns that match every url "..." and sha256 "..." line in the file — including the ones inside the pyyaml resource block. So every automated formula update overwrites the pyyaml values with the vstack sdist values.

Replace the update step with this Python-based approach, which is precise and safe:

The count=1 ensures only the first match (the top-level formula block) is touched, and the resource-scoped patterns update pyyaml independently without any risk of collision.

Summary of what you need to do

Step Repo Change
Fix broken install now eschaar/homebrew-vstack Update pyyaml resource block in Formula/vstack.rb (Fix 1)
Prevent recurrence eschaar/homebrew-vstack Replace sed update step in formula-update.yml (Fix 2)
Enable automation eschaar/vstack Merge the publish.yml PR and set HOMEBREW_TAP_ENABLED = "true"

[eschaar]

I have recently update https://github.com/eschaar/homebrew-vstack/blob/main/.github/workflows/formula-update.yml.
It should now include required dependencies into the formula automatically, so this pull request is no longer needed.