Logs ignore XDG_CACHE_HOME env variable while processing HOMEBREW_CACHE and HOMEBREW_LOGS

[Tony-Sol]

brew gist-logs <formula> link OR brew config AND brew doctor output

$ brew config                                                                                        1 2023-10-28 04:46:38
HOMEBREW_VERSION: 4.1.17
ORIGIN: https://github.com/Homebrew/brew
HEAD: 35746e0a6ba6c3c5cfe56d99f79d9ec9f52ee15f
Last commit: 6 days ago
Core tap JSON: 28 Oct 01:43 UTC
HOMEBREW_PREFIX: /home/linuxbrew/.linuxbrew
HOMEBREW_CACHE: /home/tony/.local/cache/Homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: :0
HOMEBREW_EDITOR: nvim
HOMEBREW_MAKE_JOBS: 20
Homebrew Ruby: 2.6.10 => /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/vendor/portable-ruby/2.6.10_1/bin/ruby
CPU: 20-core 64-bit unknown_0x6_0x97
Clang: N/A
Git: 2.34.1 => /bin/git
Curl: 7.81.0 => /bin/curl
Kernel: Linux 5.15.123.1-microsoft-standard-WSL2 x86_64 GNU/Linux
OS: Ubuntu 22.04.3 LTS (jammy)
WSL: 2 (Microsoft Store)
Host glibc: 2.35
/usr/bin/gcc: 11.4.0
/usr/bin/ruby: N/A
glibc: N/A
gcc@11: N/A
gcc: 13.2.0
xorg: N/A

Verification

• My "brew doctor output" says Your system is ready to brew. and am still able to reproduce my issue.
• I ran brew update and am still able to reproduce my issue.
• I have resolved all warnings from brew doctor and that did not fix my problem.
• I searched for recent similar issues at https://github.com/Homebrew/homebrew-core/issues?q=is%3Aissue and found no duplicates.

What were you trying to do (and why)?

I was trying to set homebrew's cache into specific location via HOMEBREW_CACHE env, but it's still creates ~/.cache/Homebrew directory for logs which is not a suitable path in my case

What happened (include all command output)?

What did you expect to happen?

Logs will be created in ${HOMEBREW_CACHE}/Logsas man page says

Step-by-step reproduction instructions (by running brew commands)

rm -Rf ~/.cache/Homebrew # drop old cache dir
HOMEBREW_CACHE="${HOME}/.homebrew-cache" brew <anything> # do something
ls -la ~/ # see that there are two dirs - ~/.homebrew-cache AND again ~/.cache/Homebrew/Logs

[SMillerDev]

This should be filed in Homebrew/brew since it is about the behaviour of the brew tool, not about a package.

Additionally, please don't use images to report terminal output. It makes it much harder to scale and read than just text

[apainintheneck]

The relevant code is here:

brew/Library/Homebrew/brew.sh

Lines 35 to 45 in 97eda64

	if [[ -n "${HOMEBREW_MACOS}" ]]
	then
	HOMEBREW_DEFAULT_CACHE="${HOME}/Library/Caches/Homebrew"
	HOMEBREW_DEFAULT_LOGS="${HOME}/Library/Logs/Homebrew"
	HOMEBREW_DEFAULT_TEMP="/private/tmp"
	else
	CACHE_HOME="${XDG_CACHE_HOME:-${HOME}/.cache}"
	HOMEBREW_DEFAULT_CACHE="${CACHE_HOME}/Homebrew"
	HOMEBREW_DEFAULT_LOGS="${CACHE_HOME}/Homebrew/Logs"
	HOMEBREW_DEFAULT_TEMP="/tmp"
	fi

brew/Library/Homebrew/brew.sh

Lines 78 to 80 in 97eda64

	HOMEBREW_CACHE="${HOMEBREW_CACHE:-${HOMEBREW_DEFAULT_CACHE}}"
	HOMEBREW_LOGS="${HOMEBREW_LOGS:-${HOMEBREW_DEFAULT_LOGS}}"
	HOMEBREW_TEMP="${HOMEBREW_TEMP:-${HOMEBREW_DEFAULT_TEMP}}"

Nothing looks obviously wrong though.

[Bo98]

Nothing looks obviously wrong though.

Probably an env filtering issue

[apainintheneck]

Yeah, that's exactly it. I assume we don't allow this to pass through because it could affect build reproducibility.

We need to at least pass it from bin/brew to brew.sh where these values are set. The obvious thing to do here would be to just create a new HOMEBREW_XDG_CACHE_HOME variable that we export internally with the value of XDG_CACHE_HOME if it is set.