我正在尝试编写一个用自制软件做一些东西的rubygem。我正在呼吁brew使用system()做一些事情。当我在使用bundler时包含某些gem时，我在system()内部会遇到一些错误。
例如，一个带rake的基本Gemfile：
~/tmp/foo cat Gemfile
source 'https://rubygems.org'
gem 'rake'
运行irb后的bundle install内：
irb(main):001:0> system("brew", "info", "ack")
Could not find rake-12.0.0 in any of the sources
Run `bundle install` to install missing gems.
=> false
我可以在通话中执行bundle install并收到相同的结果：
rb(main):007:0> system("bundle", "install")
Using rake 12.0.0
Using bundler 1.14.6
Bundle complete! 1 Gemfile dependency, 2 gems now installed.
Bundled gems are installed into /Users/laura/.bundle.
=> true
irb(main):008:0> system("brew", "version")
Could not find rake-12.0.0 in any of the sources
Run `bundle install` to install missing gems.
=> false
如果没有包含rake gem，我不会收到任何错误：
~/tmp/foo cat Gemfile
source 'https://rubygems.org'
gem 'git'
~/tmp/foo bundle install
Fetching gem metadata from https://rubygems.org/.
Fetching version metadata from https://rubygems.org/
Resolving dependencies...
Using git 1.3.0
Using bundler 1.14.6
Bundle complete! 1 Gemfile dependency, 2 gems now installed.
Bundled gems are installed into /Users/surminus/.bundle.
~/tmp/foo
~/tmp/foo irb
irb(main):002:0> system("brew", "info", "ack")
ack: stable 2.16, HEAD
Search tool like grep, but optimized for programmers
https://beyondgrep.com/
/usr/local/Cellar/ack/2.14 (4 files, 184.7KB)
Built from source on 2016-12-16 at 16:24:07
/usr/local/Cellar/ack/2.16 (4 files, 190.7KB) *
Built from source on 2017-03-17 at 20:25:45
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/ack.rb
=> true
我知道这可能与自制者，耙子和捆绑者之间的一些冲突有关，但我不能为我的生活找出正在发生的事情。我只需要为某些开发特定任务执行任务，这样我就可以将其删除，但我很想知道为什么会发生这种情况，或者确实以这种方式调用brew是$ bad。
编辑：我被要求在捆绑目录中输出gem list --local。似乎是系统宝石。使用bundle exec：
~/tmp/foo bundle exec gem list --local
*** LOCAL GEMS ***
bundler (1.14.6)
rake (12.0.0)
没有bundle exec：
~/tmp/foo gem list --local
*** LOCAL GEMS ***
activemodel (5.0.1)
activesupport (5.0.1)
addressable (2.5.0)
bigdecimal (1.2.8)
bundler (1.14.6, 1.14.5, 1.13.6)
CFPropertyList (2.2.8)
coderay (1.1.1)
commander (4.4.2)
concurrent-ruby (1.0.3)
did_you_mean (1.0.0)
diff-lcs (1.3, 1.2.5)
domain_name (0.5.20161129)
facter (2.4.6 ruby universal-darwin)
fileutils (0.7)
git (1.3.0)
hiera (1.3.4)
highline (1.7.8)
http-cookie (1.0.3)
i18n (0.7.0)
io-console (0.4.5)
json (2.0.2, 1.8.3)
json_pure (2.0.1, 1.8.3)
metaclass (0.0.4)
method_source (0.8.2)
mime-types (3.1)
mime-types-data (3.2016.0521)
minitest (5.10.1, 5.8.3)
mocha (1.2.1, 1.1.0)
myosx (0.2.2, 0.2.0, 0.1.0)
net-telnet (0.1.1)
netrc (0.11.0)
oauth (0.5.1)
power_assert (0.2.6)
pry (0.10.4)
psych (2.0.17)
public_suffix (2.0.4)
puppet (3.8.7)
puppet-lint (1.1.0)
puppet-syntax (2.3.0, 2.1.0)
puppetlabs_spec_helper (1.1.1)
rake (12.0.0, 11.1.2, 10.5.0, 10.4.2)
rdoc (4.2.1)
rest-client (2.0.0)
rmagick (2.16.0)
rspec (3.5.0, 3.4.0)
rspec-core (3.5.4, 3.4.4)
rspec-expectations (3.5.0, 3.4.0)
rspec-mocks (3.5.0, 3.4.1)
rspec-puppet (2.4.0)
rspec-support (3.5.0, 3.4.1)
ruby-trello (1.6.0)
slop (3.6.0)
test-unit (3.1.5)
thread_safe (0.3.5)
tzinfo (1.2.2)
unf (0.1.4)
unf_ext (0.0.7.2)