[rawsun007]

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The follow-up I named in #23996. Utils::Shell.export_value has a branch for every shell it recognises except pwsh, which falls off the end of the case and returns nil.

Reproduce:

$ brew --env --shell=pwsh
                      # twelve blank lines, exit 0
$ brew --env --shell=fish
set -gx CC "clang"
...

cmd/--env.rb:54 does puts Utils::Shell.export_value(...), so nil prints an empty line. The same nil reaches caveats.rb:98-123, so a formula that wants LDFLAGS/CPPFLAGS/PKG_CONFIG_PATH set prints "For compilers to find x you may need to set:" followed by blank lines, for anyone whose SHELL is pwsh.

Same value, five shells, before this change:

shell	export_value("LDFLAGS", "-L…/lib")
bash, zsh	export LDFLAGS="-L…/lib"
fish	set -gx LDFLAGS "-L…/lib"
tcsh	setenv LDFLAGS -L…/lib;
pwsh	nil

pwsh is not an unsupported shell here: from_path accepts it, profile maps it, set_variable_in_profile and prepend_path_in_profile both emit for it, and brew shellenv pwsh already works. export_value is the one function that does not.

The emitted form is $env:NAME = 'value', matching set_variable_in_profile, and quoting goes through the existing pwsh_quote so it's becomes 'it''s'. That helper and this exact string shape were verified against PowerShell 7.4.6 in #23996; I did not re-run a live shell for this change.

After:

$ brew --env --shell=pwsh
$env:CC = 'clang'
$env:CXX = 'clang++'
$env:MAKEFLAGS = '-j10'

export_value had no spec coverage at all, for any shell. This adds three: the pwsh line, pwsh quoting, and a bash case as a control. Reverting only utils/shell.rb fails exactly the two pwsh examples and leaves the bash one green. brew lgtm is green, and brew tests --only=caveats and --only=cmd/--env pass, since a changed-files run does not cover the callers.

AI disclosure: written by Claude Opus 5 in Claude Code on my machine. I have not read the diff line by line myself yet, so the last box stays unticked; I answer review comments myself, and no commit here is attributed to an AI.

[MikeMcQuaid]

Thanks!