feat!: Store logs under XDG_STATE_HOME

[e-kwsm]

https://specifications.freedesktop.org/basedir/0.8/#variables:

The $XDG_STATE_HOME contains state data that should persist between (application) restarts, but that is not important or portable enough to the user that it should be stored in $XDG_DATA_HOME. It may contain:

• actions history (logs, history, recently used files, …)
• current state of the application that can be reused on a restart (view, layout, open files, undo history, …)

Please read Github PR Conventions and then fill in one of these two templates.

---

Template Α: This PR modifies behaviour or interface

Include the following checklist in your PR:

• Patches conform to the coding conventions.
• Any changes that could be relevant to users have been recorded in the changelog.
  • Is the change significant? If so, remember to add significance: significant in the changelog file.
• The documentation has been updated, if necessary.
• Manual QA notes have been included.
• Tests have been added. (Ask for help if you don’t know how to write them! Ask for an exemption if tests are too complex for too little coverage!)

[philderbeast]

There is related documentation that would need to be changed alongside this *.hs change.

cabal/doc/cabal-commands.rst

Line 744 in e4d6c7c

logs-dir: /home/alice/.cabal/logs

[philderbeast]

The location can be varied with this option marked as "Not implemented yet".

cabal/doc/cabal-project-description-file.rst

Lines 1854 to 1863 in e4d6c7c

	.. cfg-field:: logs-dir: directory
	--logs-dir=DIR
	:synopsis: Directory to store build logs.
	:default: ``~/.cabal/logs``
	:strike:`The location where build logs for packages are stored.`
	Not implemented yet.
	The command line variant of this flag is ``--logs-dir=DIR``.

[e-kwsm]

Thank you for your review.

[e-kwsm]

I expect $XDG_STATE_HOME is already used because of

cabal/cabal-install/src/Distribution/Client/Config.hs

Lines 826 to 828 in d1fc7dc

	defaultStoreDir :: IO FilePath
	defaultStoreDir =
	getDefaultDir XdgState "store"

but cabal path, even HEAD version, does show no entries with fresh config:

$ ghcup install cabal -u https://github.com/haskell/cabal/releases/download/cabal-head/cabal-head-Linux-x86_64.tar.gz head
$ cabal-head --version
cabal-install version 3.17.0.0
compiled using version 3.17.0.0 of the Cabal library
$ cabal-head user-config init --force
$ cabal-head path | grep -F /.local/state
Warning: this is a debug build of cabal-install with assertions enabled.

I failed to build cabal locally, so I’m not confident if this patch change the location.

[ulysses4ever]

failed to build cabal locally, so I’m not confident if this patch change the location.

If you make sure CI succeeded, you can get binaries in the artifacts section

[e-kwsm]

@ulysses4ever Thank you for your suggestion.
By using artifacts, bd3860b updates the cabal path output messages as of master 57e070f.