$ ruby --version
ruby 2.7.2p137 (2020-10-01 revision 5445e04352) [x86_64-darwin20]
$ gem --version
3.2.16
$ bundle version
# Bundler version 2.2.16 (2021-04-09 commit 3d7bfaff25)
$ bundle install
hello
[!] There was an error parsing `Gemfile`: There are no gemspecs at /Users/tombruijn/Desktop/my-gem. Bundler cannot continue.
# from /Users/tombruijn/Desktop/my-gem/Gemfile:3
# -------------------------------------------
#
> gemspec
# -------------------------------------------