3rd party Cask - Error: ... Calling cask url do blocks is deprecated! There is no replacement.

[trinitronx]

Output of brew config

HOMEBREW_VERSION: 4.4.15-38-g9241da0
ORIGIN: https://github.com/Homebrew/brew
HEAD: 9241da0fdcc5f4080e77747ec83c86f7b697f195
Last commit: 8 days ago
Branch: master
Core tap HEAD: 7231f2e0cc657fde42a2cc69800ca4f4ca823287
Core tap last commit: 8 days ago
Core tap branch: master
Core tap JSON: 24 Dec 16:22 UTC
Core cask tap HEAD: d0cd925ca7f910e3cc335eaea867ffcb888e32d0
Core cask tap last commit: 8 days ago
Core cask tap JSON: 24 Dec 16:22 UTC
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CASK_OPTS: []
HOMEBREW_DEVELOPER: set
HOMEBREW_DISPLAY: /private/tmp/com.apple.launchd.by0ShHrAa7/org.xquartz:0
HOMEBREW_EDITOR: vim
HOMEBREW_MAKE_JOBS: 4
HOMEBREW_NO_AUTO_UPDATE: set
HOMEBREW_NO_CLEANUP_FORMULAE: llvm,terraform,opentofu,ansible,openssl
HOMEBREW_NO_INSTALL_CLEANUP: set
HOMEBREW_NO_INSTALL_FROM_API: set
HOMEBREW_SORBET_RUNTIME: set
Homebrew Ruby: 3.3.6 => /usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.3.6/bin/ruby
CPU: quad-core 64-bit broadwell
Clang: 14.0.3 build 1403
Git: 2.45.2 => /usr/local/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 12.7.6-x86_64
CLT: 14.2.0.0.1.1668646533
Xcode: 14.3.1

Output of brew doctor

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Warning: Some taps are not on the default git origin branch and may not receive
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  git -C $(brew --repo lyraphase/right2repair) checkout main
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Description of issue

I maintain a 3rd-party Tap, LyraPhase/homebrew-pcloud, which needed some special URL handling due to the application publisher's nonstandard URL scheme using a download code parameter.

To get this working, the pcloud-drive Cask used a "url do" block. Apparently, this was marked as a RuboCop warning in Homebrew/brew#18404 which was supposed to still allow 3rd-party Taps to use this functionality.

However, evidently it was later deprecated with no replacement in Homebrew/brew#18407.

Now when issuing brew commands which load this Cask, a fatal Error is returned:

brew livecheck --cask pcloud-drive
Error: pcloud-drive: Calling cask `url do` blocks is deprecated! There is no replacement.

Unfortunately the download URL for pCloud Drive has a unique download "code" parameter, so it requires usage of a url do block, or some other method to perform an API request to get the real download URL.

This was the reason that this Cask was rejected by homebrew-cask (see: Homebrew/homebrew-cask#57634). So, I opted to maintain a 3rd-parth Cask to allow for installation of this software using Homebrew.

Is there some other currently working method or workaround for doing what this Cask needs to do?

Thanks!

[alebcay]

The deprecation message is a bit misleading, you can still have some more complex logic for the url block. The logic just needs to be moved into a separate function. For example, making a contrived example out of the existing acorn cask:

cask "acorn" do
  # [...]
  def construct_url
    app_name = "A" + "c" + "o" + "r" + "n"
    "https://flyingmeat.com/download/#{app_name}-#{version}.zip"
  end

  url construct_url # calls construct_url and passes the return value of it as an input to url
  # [...]
end

For your pcloud-drive cask, a refactoring to something like the following might work (I have not tested this with pcloud-drive in particular):

cask "pcloud-drive" do
  # [...]
  def construct_url
    require "net/http"
    require "json"
    api = "https://api.pcloud.com/"
    uri = URI(api + "getpublinkdownload?code=" + code)
    response = Net::HTTP.get(uri)
    data = JSON.parse(response)
    "https://" + data["hosts"][0] + data["path"]
  end

  url construct_url
  # [...]
end

This still would not pass muster for inclusion in the main homebrew-cask repo, but it should allow working around the deprecated url do syntax.

[trinitronx]

Thanks! This worked, and I was able to implement it here. It turns out that it just needed to take the code as a function parameter.

Getting the GitHub Actions workflow to test against the right merge commit was a bit trickier due to brew update-reset being run & resetting to master always. RuboCop was still throwing those warnings on brew style or brew audit, but it was testing the old unchanged Cask Ruby code! 🤦
After fixing that, it got rid of the url do deprecation errors.