Improve messaging for missing bubblewrap

[SMillerDev]

Inspired by comments in https://github.com/orgs/Homebrew/discussions/6893

---

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same change?
• Have you added an explanation of what your changes do and why you'd like us to include them? Performance claims (e.g. "this is faster") must include Hyperfine benchmarks.
• Have you written new tests (excluding integration tests) for your changes? Here's an example.
• Have you successfully run brew lgtm (style, typechecking and tests) with your changes locally?

---

• AI was used to generate or assist with generating this PR.

---

[Copilot]

Pull request overview

This PR improves user-facing messaging when Bubblewrap (bwrap) is missing on Linux, making it clearer how to resolve Linux sandbox failures.

Changes:

• Expanded the exception text raised when bubblewrap_executable! is requested but Bubblewrap is unavailable.
• Enhanced the failure_reason for the :missing sandbox state to include an installation suggestion.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[MikeMcQuaid]

Let's dry this up to avoid duplicating this naming.

brew install bubblewrap should never actually fix this. If it does, something in our logic is incorrect as we try to auto-install it.

We could tell people to e.g. apt-get install bubblewrap if our version doesn't work.

Can you verify this is after #22669 was merged into a release? If not, that may have fixed this.

[SMillerDev]

Seems that doesn't fix it Homebrew/discussions#6893 (comment)

[MikeMcQuaid]

Thanks @SMillerDev. This seems to be a regression. Can you take a look @Bo98?

[Bo98]

Looks like it happens in both 6.0.0 and 6.0.1 so not a regression in 6.0.1. The issue also seems to be specific to --build-from-source.

It's almost certainly this:

brew/Library/Homebrew/extend/os/linux/diagnostic.rb

Lines 31 to 35 in bbba76f

	def fatal_build_from_source_checks
	(super + %w[
	check_linux_sandbox
	]).freeze
	end

That check runs before we automatically install it. Given we install it automatically, we don't need fatal_build_from_source_checks to check if it's installed.

[MikeMcQuaid]

@Bo98 thanks good catch!

[MikeMcQuaid]

#22728

[github-code-quality]

Code Coverage Overview

Languages: Ruby

Ruby / code-coverage/simplecov

The overall coverage in the chore/sandbox/linux_... branch is 79%. The coverage in the main branch is 78%.

Show a code coverage summary of the most impacted files.

File	main c6a08de	chore/sandbox/linux_... 97a0af1	+/-
search.rb	85%	75%	-10%
resource.rb	91%	84%	-7%
cmd/info.rb	77%	79%	+2%
tap.rb	88%	91%	+3%
services/cli.rb	62%	69%	+7%
extend/pathname.rb	75%	82%	+7%
cask/dsl/caveats.rb	85%	100%	+15%
cask/auditor.rb	36%	100%	+64%
extend/os/mac/api/internal.rb	0%	73%	+73%
rubocops/unreferenced_let.rb	0%	100%	+100%

---

_{Updated June 12, 2026 08:08 UTC
Code Coverage is in Public Preview. Learn more and provide us with your feedback.}