我没有在我的rails应用程序中使用Sass，在添加活动管理员后，它将sass作为依赖项添加到我的rails应用程序中。现在我运行RAILS_ENV=production rake assets:precompile --trace，它会抛出错误
rake aborted! NoMethodError: undefined method [] for nil:NilClass
我在这里附加我的Gemlock文件。这是我的active_admin.css.scss文件
@import "active_admin/mixins"; @import "active_admin/base";
GEM
remote: https://rubygems.org/
specs:
actionmailer (4.2.4)
actionpack (= 4.2.4)
actionview (= 4.2.4)
activejob (= 4.2.4)
mail (~> 2.5, >= 2.5.4)
rails-dom-testing (~> 1.0, >= 1.0.5)
actionpack (4.2.4)
actionview (= 4.2.4)
activesupport (= 4.2.4)
rack (~> 1.6)
rack-test (~> 0.6.2)
rails-dom-testing (~> 1.0, >= 1.0.5)
rails-html-sanitizer (~> 1.0, >= 1.0.2)
actionview (4.2.4)
activesupport (= 4.2.4)
builder (~> 3.1)
erubis (~> 2.7.0)
rails-dom-testing (~> 1.0, >= 1.0.5)
rails-html-sanitizer (~> 1.0, >= 1.0.2)
activeadmin (1.0.0.pre2)
arbre (~> 1.0, >= 1.0.2)
bourbon
coffee-rails
formtastic (~> 3.1)
formtastic_i18n
inherited_resources (~> 1.6)
jquery-rails
jquery-ui-rails
kaminari (~> 0.15)
rails (>= 3.2, < 5.0)
ransack (~> 1.3)
sass-rails
activejob (4.2.4)
activesupport (= 4.2.4)
globalid (>= 0.3.0)
activemodel (4.2.4)
activesupport (= 4.2.4)
builder (~> 3.1)
activerecord (4.2.4)
activemodel (= 4.2.4)
activesupport (= 4.2.4)
arel (~> 6.0)
activesupport (4.2.4)
i18n (~> 0.7)
json (~> 1.7, >= 1.7.7)
minitest (~> 5.1)
thread_safe (~> 0.3, >= 0.3.4)
tzinfo (~> 1.1)
arbre (1.0.3)
activesupport (>= 3.0.0)
arel (6.0.3)
bcrypt (3.1.10)
bootstrap_flash_messages (1.0.2)
bourbon (4.2.6)
sass (~> 3.4)
thor (~> 0.19)
builder (3.2.2)
climate_control (0.0.3)
activesupport (>= 3.0)
clndr-rails (1.2.10.1)
jquery-rails
momentjs-rails
rails (~> 4.2.0)
railties (~> 4.2.0)
underscore-rails
cocaine (0.5.7)
climate_control (>= 0.0.3, < 1.0)
coffee-rails (4.1.0)
coffee-script (>= 2.2.0)
railties (>= 4.0.0, < 5.0)
coffee-script (2.4.1)
coffee-script-source
execjs
coffee-script-source (1.9.1.1)
content_for_in_controllers (0.0.2)
daemons (1.2.3)
devise (3.5.3)
bcrypt (~> 3.0)
orm_adapter (~> 0.1)
railties (>= 3.2.6, < 5)
responders
thread_safe (~> 0.1)
warden (~> 1.2.3)
erubis (2.7.0)
eventmachine (1.0.8)
execjs (2.6.0)
faraday (0.9.2)
multipart-post (>= 1.2, < 3)
font-awesome-rails (4.5.0.0)
railties (>= 3.2, < 5.0)
foreman (0.78.0)
thor (~> 0.19.1)
formtastic (3.1.3)
actionpack (>= 3.2.13)
formtastic_i18n (0.4.1)
globalid (0.3.6)
activesupport (>= 4.1.0)
has_scope (0.6.0)
actionpack (>= 3.2, < 5)
activesupport (>= 3.2, < 5)
i18n (0.7.0)
inherited_resources (1.6.0)
actionpack (>= 3.2, < 5)
has_scope (~> 0.6.0.rc)
railties (>= 3.2, < 5)
responders
jquery-rails (4.0.5)
rails-dom-testing (~> 1.0)
railties (>= 4.2.0)
thor (>= 0.14, < 2.0)
jquery-turbolinks (2.1.0)
railties (>= 3.1.0)
turbolinks
jquery-ui-rails (5.0.5)
railties (>= 3.2.16)
json (1.8.3)
jwt (1.5.2)
kaminari (0.16.3)
actionpack (>= 3.0.0)
activesupport (>= 3.0.0)
kgio (2.10.0)
libv8 (3.16.14.7)
loofah (2.0.3)
nokogiri (>= 1.5.9)
mail (2.6.3)
mime-types (>= 1.16, < 3)
mime-types (2.6.2)
mimemagic (0.3.0)
mini_portile (0.6.2)
minitest (5.8.2)
momentjs-rails (2.10.6)
railties (>= 3.1)
multi_json (1.11.2)
multi_xml (0.5.5)
multipart-post (2.0.0)
nokogiri (1.6.6.2)
mini_portile (~> 0.6.0)
oauth (0.4.7)
oauth2 (1.0.0)
faraday (>= 0.8, < 0.10)
jwt (~> 1.0)
multi_json (~> 1.3)
multi_xml (~> 0.5)
rack (~> 1.2)
orm_adapter (0.5.0)
paperclip (4.3.1)
activemodel (>= 3.2.0)
activesupport (>= 3.2.0)
cocaine (~> 0.5.5)
mime-types
mimemagic (= 0.3.0)
polyamorous (1.3.0)
activerecord (>= 3.0)
rack (1.6.4)
rack-test (0.6.3)
rack (>= 1.0)
rails (4.2.4)
actionmailer (= 4.2.4)
actionpack (= 4.2.4)
actionview (= 4.2.4)
activejob (= 4.2.4)
activemodel (= 4.2.4)
activerecord (= 4.2.4)
activesupport (= 4.2.4)
bundler (>= 1.3.0, < 2.0)
railties (= 4.2.4)
sprockets-rails
rails-deprecated_sanitizer (1.0.3)
activesupport (>= 4.2.0.alpha)
rails-dom-testing (1.0.7)
activesupport (>= 4.2.0.beta, < 5.0)
nokogiri (~> 1.6.0)
rails-deprecated_sanitizer (>= 1.0.1)
rails-html-sanitizer (1.0.2)
loofah (~> 2.0)
railties (4.2.4)
actionpack (= 4.2.4)
activesupport (= 4.2.4)
rake (>= 0.8.7)
thor (>= 0.18.1, < 2.0)
raindrops (0.15.0)
rake (10.4.2)
ransack (1.7.0)
actionpack (>= 3.0)
activerecord (>= 3.0)
activesupport (>= 3.0)
i18n
polyamorous (~> 1.2)
ref (1.0.5)
responders (2.1.1)
railties (>= 4.2.0, < 5.1)
sass (3.4.20)
sass-rails (5.0.4)
railties (>= 4.0.0, < 5.0)
sass (~> 3.1)
sprockets (>= 2.8, < 4.0)
sprockets-rails (>= 2.0, < 4.0)
tilt (>= 1.1, < 3)
sorcery (0.9.1)
bcrypt (~> 3.1)
oauth (~> 0.4, >= 0.4.4)
oauth2 (>= 0.8.0)
spring (1.4.0)
sprockets (3.4.0)
rack (> 1, < 3)
sprockets-rails (2.3.3)
actionpack (>= 3.0)
activesupport (>= 3.0)
sprockets (>= 2.8, < 4.0)
sqlite3 (1.3.11)
therubyracer (0.12.2)
libv8 (~> 3.16.14.0)
ref
thin (1.6.4)
daemons (~> 1.0, >= 1.0.9)
eventmachine (~> 1.0, >= 1.0.4)
rack (~> 1.0)
thor (0.19.1)
thread_safe (0.3.5)
tilt (2.0.1)
turbolinks (2.5.3)
coffee-rails
tzinfo (1.2.2)
thread_safe (~> 0.1)
uglifier (2.7.2)
execjs (>= 0.3.0)
json (>= 1.8.0)
underscore-rails (1.8.3)
unicorn (5.0.1)
kgio (~> 2.6)
rack
raindrops (~> 0.7)
warden (1.2.4)
rack (>= 1.0)
will_paginate (3.0.7)
will_paginate-bootstrap (1.0.1)
will_paginate (>= 3.0.3)
PLATFORMS
ruby
DEPENDENCIES
activeadmin
bootstrap_flash_messages (~> 1.0.1)
clndr-rails
content_for_in_controllers
devise
font-awesome-rails
foreman
jquery-rails
jquery-turbolinks
paperclip
rails (= 4.2.4)
sorcery
spring
sprockets
sqlite3
therubyracer
thin
turbolinks
uglifier (>= 1.3.0)
underscore-rails
unicorn
will_paginate-bootstrap
答案 0 :(得分：0)
根据ActiveAdmin的documentation，您必须在sass-rails（以及Gemfile）中加入MetaSearch：
# Gemfile
gem 'activeadmin'
gem 'sass-rails'
gem 'meta_search'
希望它有所帮助！