Check for both shallow clones at the same time.

[rgant]

• 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?
• Have you written new tests for your changes? Here's an example.
• Have you successfully run brew style with your changes locally?
• Have you successfully run brew tests with your changes locally?
• Have you successfully run brew man locally and committed any changes?

---

I find it confusing that the first time you fail because of an shallow clone issue it only tells you about one of the shallow clones. Since the second one is very similarly named, for example #9420.

This is a terrible way to do it, but since I am completely unfamiliar with how brew is constructed it is a straightforward example of the way I think it should work.

[rgant]

euphorbus:~$ touch /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask/.git/shallow
euphorbus:~$ touch /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/.git/shallow
euphorbus:~$ subl /usr/local/Homebrew/Library/Homebrew/cmd/update.sh 
euphorbus:~$ brew update
Error:   homebrew-core is a shallow clone.
  homebrew-cask is a shallow clone.
  To `brew update`, first run:
    git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core fetch --unshallow
    git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask fetch --unshallow
  This restriction has been made on GitHub's request because updating shallow
  clones is an extremely expensive operation due to the tree layout and traffic of
  Homebrew/homebrew-core and Homebrew/homebrew-cask. We don't do this for you
  automatically to avoid repeatedly performing an expensive unshallow operation in
  CI systems (which should instead be fixed to not use shallow clones). Sorry for
  the inconvenience!
euphorbus:~$ rm /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/.git/shallow
remove /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/.git/shallow? y
euphorbus:~$ brew update
Error:   
  homebrew-cask is a shallow clone.
  To `brew update`, first run:
    
    git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask fetch --unshallow
  This restriction has been made on GitHub's request because updating shallow
  clones is an extremely expensive operation due to the tree layout and traffic of
  Homebrew/homebrew-core and Homebrew/homebrew-cask. We don't do this for you
  automatically to avoid repeatedly performing an expensive unshallow operation in
  CI systems (which should instead be fixed to not use shallow clones). Sorry for
  the inconvenience!
euphorbus:~$ rm /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask/.git/shallow
remove /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask/.git/shallow? y
euphorbus:~$ brew update
Updated 2 taps (homebrew/core and homebrew/cask).

[maxim-belkin]

I don't like empty lines in the output. The following produces a better result (suppresses empty lines) but I can't say that I'm a big fan of how this code looks so let's see what other maintainers think about it.

  [[ -f "$HOMEBREW_LIBRARY/Taps/homebrew/homebrew-core/.git/shallow" ]] && SHALLOW_CORE=1
  [[ -f "$HOMEBREW_LIBRARY/Taps/homebrew/homebrew-cask/.git/shallow" ]] && SHALLOW_CASK=1

  if [[ -n $SHALLOW_CORE || -n $SHALLOW_CASK ]]
  then
    odie <<EOS
${SHALLOW_CORE:+homebrew-core is a shallow clone.${SHALLOW_CASK:+
       }}${SHALLOW_CASK:+\
homebrew-cask is a shallow clone.}
To \`brew update\`, first run:
  ${SHALLOW_CORE:+git -C "$HOMEBREW_LIBRARY/Taps/homebrew/homebrew-core" fetch --unshallow${SHALLOW_CASK:+
}}${SHALLOW_CASK:+\
  git -C "$HOMEBREW_LIBRARY/Taps/homebrew/homebrew-cask" fetch --unshallow}
This restriction has been made on GitHub's request because updating shallow
clones is an extremely expensive operation due to the tree layout and traffic of
Homebrew/homebrew-core and Homebrew/homebrew-cask. We don't do this for you
automatically to avoid repeatedly performing an expensive unshallow operation in
CI systems (which should instead be fixed to not use shallow clones). Sorry for
the inconvenience!
EOS
  fi

[MikeMcQuaid]

Thanks for opening a PR @rgant ❤️

I don't like empty lines in the output

Agreed 👍🏻

[rgant]

I would imagine that 99.999 times out of 100 it would be both repos are shallow or neither are (once this message is the default instructing you to fix both at the same time). So making it look nice when there is only one feels like polishing an edge case. But if you want to do it then I've added my way of doing that.

euphorbus:~$ brew update
Error:   
    homebrew-cask is a shallow clone.
  To `brew update`, first run:
    git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask fetch --unshallow
  This restriction has been made on GitHub's request because updating shallow
  clones is an extremely expensive operation due to the tree layout and traffic of
  Homebrew/homebrew-core and Homebrew/homebrew-cask. We don't do this for you
  automatically to avoid repeatedly performing an expensive unshallow operation in
  CI systems (which should instead be fixed to not use shallow clones). Sorry for
  the inconvenience!
euphorbus:~$ touch /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/.git/shallow
euphorbus:~$ brew update
Error:   
    homebrew-core is a shallow clone.
    homebrew-cask is a shallow clone.
  To `brew update`, first run:
    git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core fetch --unshallow
    git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask fetch --unshallow
  This restriction has been made on GitHub's request because updating shallow
  clones is an extremely expensive operation due to the tree layout and traffic of
  Homebrew/homebrew-core and Homebrew/homebrew-cask. We don't do this for you
  automatically to avoid repeatedly performing an expensive unshallow operation in
  CI systems (which should instead be fixed to not use shallow clones). Sorry for
  the inconvenience!
euphorbus:~$ rm /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask/.git/shallow
remove /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask/.git/shallow? y
euphorbus:~$ brew update
Error:   
    homebrew-core is a shallow clone.
  To `brew update`, first run:
    git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core fetch --unshallow
  This restriction has been made on GitHub's request because updating shallow
  clones is an extremely expensive operation due to the tree layout and traffic of
  Homebrew/homebrew-core and Homebrew/homebrew-cask. We don't do this for you
  automatically to avoid repeatedly performing an expensive unshallow operation in
  CI systems (which should instead be fixed to not use shallow clones). Sorry for
  the inconvenience!

[maxim-belkin]

Thank you, @rgant! Looks great!

[MikeMcQuaid]

Thanks so much for your first contribution! Without people like you submitting PRs we couldn't run this project. You rock, @rgant!