环境变量为何能让 Ruby 快十倍

Why environment variables could slow down your Ruby scripts for 10 times

https://www.youtube.com/watch?v=A1V-vZklVLY

Transcript

1. 辘हݒᰁ

   ԅ֜胼ᦏ Ruby 盠܈狝
   笳碭ቡ
   

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2. य़疑অ, ౯ݞ笳碭ቡ
   github.com/pmq20
   twitter
   @psvr
   

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6. GitLab 耬ᵅ #15452
   “On average it seems to take around 13 seconds to
   cherry-pick commits for GitLab CE. Most of the time
   appears to be spent in GitHooksService#execute
   (around 10 seconds on average).”
   – Yorick Peterse
   

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7. GitLab 耬ᵅ #15452
   https://gitlab.com/gitlab-org/gitlab-ce/issues/15452
   

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8. GitLab 耬ᵅ #15452
   https://gitlab.com/gitlab-org/gitlab-ce/issues/15452
   system(…pre-receive…)
   

   system(…update…)
   system(…post-receive…)
   

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9. Kernel#system
   

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10. ಗᤈ෸ᳵᕅ 60ms ጱ Ruby 郥๜
    

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11. አ system ݄᧣疰ݒ౮ԧ 600ms
    

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12. 簁ᘒ unsetenv_others ݢ盵瓰蝧ଶ
    

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13. ٌਙᥡ疗ᕮຎ
    • “./update” ஠ᶳԅ Ruby 纷ଧ牧覍 Ruby 犋瓰ሿ
    • “./update” ݢ覍ଉᓌܔ牧 Hello World ܨݢ瓰ሿ
    

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14. [demo]
    

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15. unsetenv_others ฎՋԍ牫
    • 蟴ᗝฎ玽竃ቘ辘हݒᰁ
    • ୮ unsetenv_others: true ෸牧霙ᤈक़蟂纷ଧ獮竃ቘ
    ಅ磪辘हݒᰁ牧ᴻ覍ฎก繊瞲ਧጱݒᰁ
    • ୮ unsetenv_others: false ෸牧犋竃ቘҁ认ᦊᤈԅ҂
    

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16. gitlab-ce: MR-3939
    https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3939
    

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17. – Yorick Peterse
    “I'm a bit confused, how does unsetting
    environment variables make things run faster?”
    

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18. – Douwe Maan
    “The measurements don't lie, but I'm not quite
    sure why this works either. Can you elaborate?”
    

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19. चᏐᎣᦩ
    

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20. ྯӻᬰ纷᮷磪ᛔ૩ጱᆿᬰ纷
    ྯӻᬰ纷᮷ฎݚӞӻᬰ纷貉ۖጱ
    

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21. ྯӻᬰ纷᮷磪ᛔ૩ᇿ缏ጱ辘हݒᰁ
    

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22. ྯӻᬰ纷᮷磪ᛔ૩ᇿ缏ጱ辘हݒᰁ
    

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23. ৼᬰ纷՗ᆿᬰ纷Ӿᖀ瞚辘हݒᰁ
    

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24. ֕ৼᬰ纷犋胼狕硬ᆿᬰ纷ጱ辘हݒᰁ
    

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25. വᦞ1
    辘हݒᰁ鋓ᬰ纷ᕮ๳ᘒ窞犜
    ҁshell ฎ IRB ጱᆿᬰ纷҂
    

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26. വᦞ2
    窔ኞৼᬰ纷ݢ皤ᖅᆿᬰ纷辘हݒᰁጱኞ޸珏๗
    ҁIRB ฎ shell ጱᆿᬰ纷҂
    

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27. ᆿᬰ纷磪ߺ犚ݢ綡ጱ辘
    हݒᰁ᭳փᕳԧৼᬰ纷牫
    

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28. BUNDLE_BIN_PATH
    /Users/pmq20/.rvm/gems/ruby-2.1.8/
    gems/bundler-1.12.4/exe/bundle
    BUNDLE_GEMFILE
    /Users/pmq20/gitlab-development-
    kit/gitlab/Gemfile
    BUNDLE_ORIG_GEM_PATH
    /Users/pmq20/.rvm/gems/
    ruby-2.1.8:/Users/pmq20/.rvm/gems/
    ruby-2.1.8@global
    BUNDLE_ORIG_MANPATH /usr/local/man:
    

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29. GEM_HOME /Users/pmq20/.rvm/gems/ruby-2.1.8
    GEM_PATH
    /Users/pmq20/.rvm/gems/
    ruby-2.1.8:/Users/pmq20/.rvm/gems/
    ruby-2.1.8@global
    RUBYLIB
    /Users/pmq20/.rvm/gems/ruby-2.1.8/
    gems/bundler-1.12.4/lib
    RUBYOPT -rbundler/setup
    

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30. RUBY_VERSION ruby-2.1.8
    rvm_bin_path /Users/pmq20/.rvm/bin
    rvm_path /Users/pmq20/.rvm
    rvm_prefix /Users/pmq20
    

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31. ᇨՈ΅͠獮Ͷ牦
    

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32. GEM_HOME /Users/pmq20/.rvm/gems/ruby-2.1.8
    GEM_PATH
    /Users/pmq20/.rvm/gems/
    ruby-2.1.8:/Users/pmq20/.rvm/gems/
    ruby-2.1.8@global
    RUBYLIB
    /Users/pmq20/.rvm/gems/ruby-2.1.8/
    gems/bundler-1.12.4/lib
    RUBYOPT -rbundler/setup
    

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33. RUBYOPT
    man ruby
    

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34. e.g.
    

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35. ৼᬰ纷ᖀ瞚ԧᆿᬰ纷ጱ
    RUBYOPT=-rbundler/setup
    

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36. ᘒ bundler/setup ಗᤈ盄眸
    ࢩ種ৼᬰ纷ಗᤈ盄眸
    

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37. 簁ᘒक़蟂 shell ๚ਧԎᧆݒᰁ
    

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38. 貉ۖ Rails ݸ಍磪ԧᧆݒᰁ
    

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39. RUBYOPT=-rbundler/setup
    ՗֜ᘒ๶牫
    

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40. ᆿᬰ纷ฎአ bin/rails 貉ۖጱ
    

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41. bin/rails ᧣አԧ config/boot
    

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42. config/boot ᧣አԧ bundler/setup
    

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43. bundler/setup ᦡਧԧ
    RUBYOPT=-rbundler/setup
    ࢩ種 bundler/setup ฎٍ磪փ礕௔ጱ
    bundler ᦏಅ磪 bundler ᓕቘጱᬰ纷ጱৼᬰ纷᮷ᤩ bundler ᓕቘ
    

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44. bundler/setup

    ฎՋԍ牫
    

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45. bundler/setup ฎӞӻ෈կ
    

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46. bundler/setup ጱֵአ࣋ว
    • bin/rails ᧣አԧ bundler/setup
    • bundle exec * ᧣አԧ bundler/setup
    • bundle show * ᧣አԧ bundler/setup
    • bundle bin-stubs ጱኞ౮ᇔ᮷᧣አԧ bundler/setup
    • ࢩ種 bundler/setup پԒฎ Ruby 貉ۖ鉑纷ጱຽ蟴
    

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47. bundler/setup ጱᦡᦇፓຽ
    • “make your code see just the dependencies that it
    should see and nothing else”
    • 矒ګঅ gem ପጱے᫹᪠趥矾ᔱᶲଧ
    • ᦏ纷ଧ௴অ胼୚አک Gemfile Ӿ瞲ਧጱ粚๜ጱପ
    • ᘒӬ獡ฎ Gemfile Ӿ๚瞲ਧጱ gem ᮷犋ݢᥠ
    

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48. Kernel#require
    • require ‘thing’
    • ইຎ ‘thing’ ૪ᕪے᫹鉑牧ಗᤈᕮ๳
    • 玽ڞ螁ܲ $LOAD_PATH ($:) ತک ‘thing’ ଚے᫹ԏ
    • 舙ತ犋کڞಲڊ LoadError
    

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49. rubygems/core_ext/
    kernel_require.rb
    • ᯿碝಑୏ Kernel ଚ remove_method ധԧ :require
    • ᯿碝ਧԎԧ Kernel#require
    • ᛔ Ruby 1.9 犥๶ RubyGems ฎٖᗝጱଚᛔۖ貉አ
    • ᛔ Ruby 1.9 犥๶鉖಍ฎ Kernel#require ጱ፥ྋᶎፓ
    

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50. rubygems/core_ext/
    kernel_require.rb
    • require ‘thing’
    • ইຎ ‘thing’ ૪ᕪے᫹鉑牧ಗᤈᕮ๳
    • 玽ڞ螁ܲ $LOAD_PATH ($:) ತک ‘thing’ ଚے᫹ԏ
    • 玽ڞ՗૪ਞᤰጱ gem Ӿ੔ತ ‘thing’ ଚ಩ᧆ gem ጱ
    ᪠趥ے獈 $LOAD_PATH ($:)
    • 舙ತ犋کڞಲڊ LoadError
    

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51. 牬demo]
    require pry, edit require
    

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52. bundler/setup ࣁ狶Ջԍ
    • ತکӞᕟ粬ਧ粚๜ጱ gem牧玲ڊ犢ժጱ gemspec
    • ಩ਙժጱ lib/ ፓ趟ጱᕷ੒᪠趥ے獈 $LOAD_PATH牧
    犥׎ Ruby ݢ犥 require ک粬ਧ粚๜ጱ gem
    • “unpatch”物݄ധ rubygems/core_ext/
    kernel_require.rb ጱ鉪ᬋ牧犥׎贶ሿ“獡ฎ Gemfile
    Ӿ๚瞲ਧጱ gem ᮷犋ݢᥠ”
    

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53. 牬demo]
    reverse_rubygems_kernel_mixin
    

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54. – hooopo
    “ഝ᧔牧Bundler ޾ Rubygems ᥝݳଚԧ”
    

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55. – huacnlee
    “疰ᧆݳଚ牧ݶ遞ጱӳᥜ”
    

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56. ෸ᳵ᮷݄ߺدԧ牫
    

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57. Bundler::Resolver.resolve
    • 臺ᩇԧ踞ጯྺᑁጱಗᤈ෸ᳵ
    • ತک磧犭ጱ gem ᕟݳ牧ֵ஑犢ժݢჿ᪃粬ਧጱ狅ᩢ
    ޾ৼ狅ᩢ蹇կҁܨ Gemfile + Gemfile.lock҂
    • ᬌ獈物Ӟᕟ狅ᩢ蹇կҁܨ Gemfile + Gemfile.lock҂
    • ᬌڊ物Ӟᕟ gemspec
    

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58. Gemfile.lock ጱᦡᦇ௏మ
    • 薹ຉਠ Gemfile ݸ಩ᕮຎᖨਂӥ๶ጱӞӻ๢ګ
    • ۱珀 “exact versions of all of the gems that you
    used the last time you know for sure that the
    application worked”
    • 犌 npm 2 / npm 3 ᦡᦇ௏మጱ੒穉
    

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59. Gemfile 犌 Gemfile.lock 

    ݢ胼ڊሿ犋ݶྍ
    • ࣁ૪磪 Gemfile.lock ጱ眐٭ӥ牧አಁๅ碝ԧ Gemfile
    ᘒဌ磪᯿碝 bundle牧ڞ Gemfile.lock 鉑๗
    • 舙羬ᕹ૪磪胼ჿ᪃ Gemfile 碝襑穩ጱ gem牧ڞ貉ۖ
    ଫአ෸ᛔۖๅ碝 Gemfile.lock
    • 舙羬ᕹჿ᪃犋ԧ Gemfile ጱ碝襑穩牧ڞಸᲙ
    • ࢩ種ྯ稞貉ۖ᮷ᥝ᯿碝薹 Gemfile + Gemfile.lock
    

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60. Molinillo ᓒဩ
    • Ӟӻ蝢አጱ狅ᩢ穩薹ᓒဩ
    • 玲ᛔ CocoaPods
    • ᬌ獈物狅ᩢ蹇կ҄狅ᩢᲁਧࢶ
    • ᬌڊ物狅ᩢ薹ࢶ
    

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61. 禊盢ು虡
    • search_for(dependency) አ๶矾ᔱჿ᪃ᕳਧ狅ᩢጱ狅ᩢᥢ໒
    • dependencies_for(specification) አ๶蜴ࢧᕳਧᥢ໒ጱ狅ᩢ
    • requirement_satisfied_by?(requirement, activated, spec) ࣁ୮
    獮ጱ狅ᩢࢶ activated Ӿᦇᓒ requirement ฎ玽胼ᤩ spec ჿ᪃
    • sort_dependencies(dependencies, activated, conflicts) ԅ൉
    ṛ௔胼牧ೲ“਻ฃ薹”ጱᶲଧ矎ଧ dependencies
    ؃ᦡਂࣁӞӻ“狅ᩢᥢ໒൉׀ᘏ”牧ਙ贶ሿইӥොဩ
    

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62. Molinillo ᓒဩጱ௏᪠
    च๜௏మ——ࢧშဩ
    

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63. ຾
    ᇫாᦡᦇ
    - ୮獮ጱ襑穩ጱݷਁ
    - ୮獮੢๚ჿ᪃ጱ襑穩褸ݳ
    - ୮獮蟂獤薹牧ܨ૪筕ၚጱ狅ᩢࢶ
    - ୮獮ጱ襑穩
    - ୮獮ጱ襑穩ጱݢᤈ薹褸
    - 鉟趞窼ଶ
    - ٫统褸
    

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64. 狅ᩢா
    ܨӞञ襑穩޾Ӟञݢᤈ薹
    ݢᤈ薹ா
    ܨӞञ襑穩޾Ӟӻݢᤈ薹
    ຾
    

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65. Ԇ盌辘
    ݝᥝ୮獮ᇫா鉕磪୮獮੢๚ჿ
    ᪃ጱ襑穩疰ᖀᖅ盌辘
    ڡত狅ᩢா
    

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66. ੤ᦶ碝ጱݢᤈ薹
    ڡত狅ᩢா
    ݢᤈ薹ா
    …
    狅ᩢா
    ڡত狅ᩢா
    …
    狅ᩢா
    蟂獤薹ࢶӾฎ玽૪珀ᧆ薹牫ฎ玽ჿ᪃粚๜ᥝ穩牫

    ฎ玽ჿ᪃ Gemfile.lock牫
    ੤ᦶ筕ၚᧆݢᤈ薹
    

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67. ੤ᦶ碝ጱݢᤈ薹
    ڡত狅ᩢா
    ݢᤈ薹ா
    …
    狅ᩢா
    ڡত狅ᩢா
    …
    狅ᩢா
    舙०ᨳ牧ᦕ趟٫统牧ࢧშ
    

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68. ຾绚෫薹
    ݱᐿࢧშ
    ڡত狅ᩢா
    …
    ୮獮ᇫா
    

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69. Ԇ盌辘
    ڡত狅ᩢா
    …
    ୮獮ᇫா
    ڡত狅ᩢா
    …
    薹ா

    ෫ๅग़襑穩
    ୮獮蟂獤薹ܨ磧ᕣ薹
    玲૪筕ၚጱ狅ᩢࢶ蜴ࢧ
    

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70. Molinillo ᓒဩጱ෸ᳵ瓰ᄖଶ
    • ᇫா绚ᳵጱय़ੜ 犔犥 ᇫா᫨ᑏጱᩇአ
    • ᇫா绚ᳵጱय़ੜ玲豙ԭ物狅ᩢ޾ৼ狅ᩢጱ踞ᰁ(m)牧
    ݢ鉝ጱ粚๜ጱ磧य़踞ᰁ(n)牧n^m
    • O(n^m)
    • 贶ᴬኼ犭牧ଃ磪獮ᗝᶼၥ獶ຏ
    

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71. 盥綡
    • ྯ稞貉ۖጱ෸狡ಗᤈ Molinillo ᓒဩ፥ጱ஠ᥝހ牫
    • Gemfile + Gemfile.lock ጱݶྍ௔፥ጱ盄᯿ᥝހ牫
    • ᇚᇗྯ稞貉ۖ Ruby 纷ଧጱ硳ሲ牧绗ᒌഘ๶ԧՋԍ牫
    • Gemfile.lock ጱᦡᦇฎ஠ᶳጱހ牫
    

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72. ᥝ犋൉ӻ Issue / PR牫
    

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73. 犡ଙ 5์26෭

    磪Ո൉鉑ԧ
    https://github.com/bundler/bundler/pull/4618
    

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75. – Jason Frey
    “You know, you really shouldn't be resolving if
    you have a lockfile...”
    

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76. – Joe Rafaniello
    “Properly detect path spec changes to avoid
    needless re-resolve”
    

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77. If there were no changes,
    just use the resolution
    from Gemfile.lock.
    

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80. ੒穉 Rails ٖ蟂᧣አ 犌 ፗ矑᧣አ

    ௔胼ഖ聻磪ಅ犋ݶ
    

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83. ܻࢩ
    • bundler/setup ԏݸ牧य़ᰁጱ辘हݒᰁᤩ狕硬ҁই
    BUNDLE_GEMFILE牏RUBYLIB牏RUBYOPT牏
    BUNDLE_BIN_PATH 缛҂
    • ৼᬰ纷ᤩ貉ۖ෸ᖀ瞚ԧᆿᬰ纷ጱ辘हݒᰁҁই
    BUNDLE_GEMFILE牧ܨ Gemfile ጱ֖ᗝ҂
    • ࢩ種୮ৼᬰ纷ᤩ貉ۖ෸牧ᆿᬰ纷ጱ Gemfile 蚏֢አ牧
    ৼᬰ纷ጱ Gemfile ᤩ஺ኼ
    

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84. 薹豙ො礯物
    Bundler.with_clean_env
    

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86. Clean environment variables when
    running git hooks
    https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/
    6344
    

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89. 玱௏
    • ஠ᶳ RUBYOPT=-rbundler/setup ހ牫
    • bundler/setup ፥ጱ磪஠ᥝฎփ礕௔ጱހ牫
    

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90. 硽ᦒ
    • 犋ᥝ蝈מ๦শ牧ྯ稞᯿碝 resolve ଚ犋ฎกฬጱᦡᦇ
    • 犋੒ጱ瑿ො疰ᥝ玄碁᧔ڊ๶牧疰猟 Jason Frey ᮎ໏
    • ྯӻՈ᮷磪ݢ胼ݎሿଚ狕瓰 bug牧鉖ฎ୏რጱঅ賳
    

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91. 硽ᦒ
    • ൉Իᤑӟԏ獮ض፡Ӟӥฎ玽磪Ո൉Ի鉑牧౲ҁๅٍݢ
    砺֢瑿҂ض礚፡磧碝୏ݎ獤ඪฎ玽Ֆ磪ᳯ᷌
    • ࣙ瞱܋ᕆ gem ک磧碝粚๜ҁ bundler 1.13 vs 1.12҂
    • 犭玕অ Bundler牧Ruby ጱ貉ۖ෸ᳵݢ犥盠܈狝牦
    

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92. ᨀᨀ
    

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93. https://github.com/pmq20
    

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