Error: Directory not empty @ dir_s_rmdir problem with 'pokerstars' on 10.14

[core-code]

General troubleshooting steps

• [x] I have retried my command with --force and the issue is still present.
• [x] I have checked the instructions for reporting bugs.
• [x] I made doubly sure this is not a checksum does not match error.
• [x] I ran brew update-reset && brew update and retried my command.
• [x] I ran brew doctor, fixed as many issues as possible and retried my command.
• [x] I checked there are no open issues for the same problem.
• [x] I understand that if I ignore these instructions, my issue may be closed without review.

Description of issue

fetching or installing 'pokerstars' fails reproducibly on my 10.14 mac, while it succeeds on the 10.13 mac. furthermore, trying to fetch or install pokerstars leaves HBC permanently in a broken state that prints:

Error: Directory not empty @ dir_s_rmdir - /Users/julian/Library/Caches/Homebrew/downloads/7bace04dd614b985e50dd1a8a28bcd79320c25bb3e406b013e5d85f1f7f2d037--

which can only be solved by emptying the cache manually

Command that failed

brew cask fetch pokerstars

Output of command with --force --verbose --debug

Julians-MBP:~ julian$ brew cask --force --verbose --debug install pokerstars
==> Cask::Installer#install
==> Printing caveats
==> Cask::Installer#fetch
==> Satisfying dependencies
==> Downloading
/usr/bin/curl -q --show-error --user-agent Homebrew/1.7.6-109-g4245635\ \(Macintosh\;\ Intel\ Mac\ OS\ X\ 10.14\)\ curl/7.54.0 --location --silent --head http://www.pokerstars.uk/PokerStarsUK.app.zip
==> Downloading http://www.pokerstars.uk/PokerStarsUK.app.zip
/usr/bin/curl -q --show-error --user-agent Homebrew/1.7.6-109-g4245635\ \(Macintosh\;\ Intel\ Mac\ OS\ X\ 10.14\)\ curl/7.54.0 --location --silent --head http://www.pokerstars.uk/PokerStarsUK.app.zip
==> Downloading from https://www.pokerstars.pt/
/usr/bin/curl -q --show-error --user-agent Homebrew/1.7.6-109-g4245635\ \(Macintosh\;\ Intel\ Mac\ OS\ X\ 10.14\)\ curl/7.54.0 --fail --location --remote-time --continue-at 0 --output /Users/julian/Library/Caches/Homebrew/downloads/7bace04dd614b985e50dd1a8a28bcd79320c25bb3e406b013e5d85f1f7f2d037--/.incomplete https://www.pokerstars.pt/
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 39182    0 39182    0     0  92094      0 --:--:-- --:--:-- --:--:-- 92192
Error: Download failed on Cask 'pokerstars' with message: Is a directory @ rb_file_s_rename - (/Users/julian/Library/Caches/Homebrew/downloads/7bace04dd614b985e50dd1a8a28bcd79320c25bb3e406b013e5d85f1f7f2d037--/.incomplete, /Users/julian/Library/Caches/Homebrew/downloads/7bace04dd614b985e50dd1a8a28bcd79320c25bb3e406b013e5d85f1f7f2d037--/)
/usr/local/Homebrew/Library/Homebrew/download_strategy.rb:299:in `rename'
/usr/local/Homebrew/Library/Homebrew/download_strategy.rb:299:in `rename'
/usr/local/Homebrew/Library/Homebrew/download_strategy.rb:299:in `block in fetch'
/usr/local/Homebrew/Library/Homebrew/utils.rb:402:in `ignore_interrupts'
/usr/local/Homebrew/Library/Homebrew/download_strategy.rb:297:in `fetch'
/usr/local/Homebrew/Library/Homebrew/cask/download.rb:40:in `fetch'
/usr/local/Homebrew/Library/Homebrew/cask/download.rb:18:in `perform'
/usr/local/Homebrew/Library/Homebrew/cask/installer.rb:146:in `download'
/usr/local/Homebrew/Library/Homebrew/cask/installer.rb:62:in `fetch'
/usr/local/Homebrew/Library/Homebrew/cask/installer.rb:90:in `install'
/usr/local/Homebrew/Library/Homebrew/cask/cmd/install.rb:21:in `block in run'
/usr/local/Homebrew/Library/Homebrew/cask/cmd/install.rb:14:in `each'
/usr/local/Homebrew/Library/Homebrew/cask/cmd/install.rb:14:in `run'
/usr/local/Homebrew/Library/Homebrew/cask/cmd/abstract_command.rb:34:in `run'
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:89:in `run_command'
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:155:in `run'
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:120:in `run'
/usr/local/Homebrew/Library/Homebrew/cmd/cask.rb:7:in `cask'
/usr/local/Homebrew/Library/Homebrew/brew.rb:91:in `<main>'
Error: Kernel.exit
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:160:in `exit'
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:160:in `rescue in run'
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:143:in `run'
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:120:in `run'
/usr/local/Homebrew/Library/Homebrew/cmd/cask.rb:7:in `cask'
/usr/local/Homebrew/Library/Homebrew/brew.rb:91:in `<main>'

Output of brew cask doctor

Julians-MBP:~ julian$ brew cask doctor
==> Homebrew Version
1.7.6-109-g4245635
==> macOS
10.14
==> SIP
Disabled
==> Java
N/A
==> Gatekeeper support
Enabled
==> Homebrew Cask Install Location
<NONE>
==> Homebrew Cask Staging Location
/usr/local/Caskroom
==> Homebrew Cask Taps:
/usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask (4038 casks)
/usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask-versions (204 casks)
/usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask-eid (11 casks)
/usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask-fonts (1180 casks)
/usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask-drivers (152 casks)
==> Contents of $LOAD_PATH
/usr/local/Homebrew/Library/Homebrew/vendor/bundle-standalone/bundler/../ruby/2.3.0/gems/ruby-macho-2.1.0/lib
/usr/local/Homebrew/Library/Homebrew/vendor/bundle-standalone/bundler/../ruby/2.3.0/gems/plist-3.4.0/lib
/usr/local/Homebrew/Library/Homebrew/vendor/bundle-standalone/bundler/
/usr/local/Homebrew/Library/Homebrew/vendor/bundle-standalone/bundler/../ruby/2.3.0/gems/backports-3.11.4/lib
/usr/local/Homebrew/Library/Homebrew/vendor/bundle-standalone/bundler/../ruby/2.3.0/gems/activesupport-5.2.1/lib
/usr/local/Homebrew/Library/Homebrew/vendor/bundle-standalone/bundler/../ruby/2.3.0/gems/tzinfo-1.2.5/lib
/usr/local/Homebrew/Library/Homebrew/vendor/bundle-standalone/bundler/../ruby/2.3.0/gems/thread_safe-0.3.6/lib
/usr/local/Homebrew/Library/Homebrew/vendor/bundle-standalone/bundler/../ruby/2.3.0/gems/minitest-5.11.3/lib
/usr/local/Homebrew/Library/Homebrew/vendor/bundle-standalone/bundler/../ruby/2.3.0/gems/i18n-1.1.0/lib
/usr/local/Homebrew/Library/Homebrew/vendor/bundle-standalone/bundler/../ruby/2.3.0/gems/concurrent-ruby-1.0.5/lib
/Library/Ruby/Gems/2.3.0/gems/did_you_mean-1.0.0/lib
/Library/Ruby/Site/2.3.0
/Library/Ruby/Site/2.3.0/x86_64-darwin18
/Library/Ruby/Site/2.3.0/universal-darwin18
/Library/Ruby/Site
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/vendor_ruby/2.3.0
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/vendor_ruby/2.3.0/x86_64-darwin18
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/vendor_ruby/2.3.0/universal-darwin18
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/vendor_ruby
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/x86_64-darwin18
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/universal-darwin18
/usr/local/Homebrew/Library/Homebrew
==> Environment Variables
LC_ALL="en_US.UTF-8"
PATH="/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/Homebrew/Library/Homebrew/shims/scm"
SHELL="/bin/bash"
Julians-MBP:~ julian$ 

Output of brew tap

Julians-MBP:~ julian$ brew tap
homebrew/cask
homebrew/cask-drivers
homebrew/cask-eid
homebrew/cask-fonts
homebrew/cask-versions
homebrew/core
homebrew/services
vitorgalvao/tiny-scripts

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.