refactor: use std errors

[janishorsts]

This PR migrates error handling from archived third-party dependencies (github.com/pkg/errors and github.com/hashicorp/go-multierror) to Go standard library patterns.

Changes

• Standard Errors: Replaced pkg/errors with standard library "errors" and "fmt" (%w wrapping and errors.AsType).
• Multi-Errors: Replaced go-multierror with standard errors.Join.
• Cleanup: Removed the obsolete stack-trace printing in cmd/earthly/app/run.go.
• Optimization: Optimized the WriterSub struct layout to reduce GC scan overhead (pointer bytes down to 40) and resolved style lints.
• Dependencies: Removed both error libraries from go.mod and go.sum.

[github-actions]

➖ Are we earthbuild yet?

No change in "earthly" occurrences

📈 Overall Progress

Branch	Total Count
main	5340
This PR	5340
Difference	+0

---

Keep up the great work migrating from Earthly to Earthbuild! 🚀

💡 Tips for finding more occurrences

Run locally to see detailed breakdown:

./.github/scripts/count-earthly.sh

Note that the goal is not to reach 0.
There is anticipated to be at least some occurences of earthly in the source code due to backwards compatibility with config files and language constructs.

[gemini-code-assist]

Code Review

This pull request refactors the codebase to replace the third-party github.com/pkg/errors package with the Go standard library's errors and fmt packages, utilizing fmt.Errorf with %w for error wrapping and errors.Join for combining errors. The review feedback highlights a critical compilation error in ls_cmds.go due to the use of a non-existent errors.AsType function. Additionally, the feedback points out several instances of redundant or duplicate error wrapping, such as wrapping the same error twice in bootstrap_cmds.go, string concatenation inside fmt.Errorf in git.go, and duplicating the error message in shell_shared.go by both formatting and wrapping the error.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.