为什么即使在“gem install io-console”之后，io/console 也会出现 LoadError？

Question

如果我这样做：

rails 生成控制器欢迎索引

我明白了：

/usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:251:in `require': 无法加载此类文件 -- io/console (LoadError)

但我的 gem 列表显示控制台已安装：

宝石清单

* 本地宝石 *

actionmailer (3.2.17)

动作包 (3.2.17)

活动模型（3.2.17）

活动记录 (3.2.17)

活动资源（3.2.17）

主动支持 (3.2.17)

arel (3.0.3)

大十进制 (1.2.5, 1.2.0)

建造者 (3.0.4)

捆绑器 (1.6.2)

咖啡轨 (3.2.2)

咖啡脚本 (2.2.0)

咖啡脚本源 (1.7.0)

erubis (2.7.0)

execjs (2.0.2)

远足 (1.2.3)

i18n (0.6.9)

io 控制台 (0.4.2)

旅程（1.0.4）

jquery-rails (3.1.0)

json (1.8.1, 1.7.7)

邮件 (2.5.4)

mime 类型 (1.25.1)

multi_json (1.9.2)

多语言 (0.3.4)

心理 (2.0.5, 2.0.0)

机架 (1.4.5)

机架缓存 (1.2)

机架-ssl (1.3.4)

机架测试 (0.6.2)

导轨 (3.2.17)

铁路 (3.2.17)

耙子 (10.3.0)

rdoc (4.1.1, 4.0.1, 3.12.2)

萨斯（3.3.5）

sass-rails (3.2.6)

链轮 (2.2.2)

sqlite3 (1.3.9)

雷神 (0.19.1)

倾斜 (1.4.1)

树顶（1.4.15）

tzinfo (0.3.39)

丑化器（2.5.0）

以 root 身份运行。

如果我这样做：

宝石环境

我明白了：

RubyGems 环境：

RUBYGEMS 版本：2.0.14

RUBY 版本：2.0.0（2014-02-24 补丁级别 451）[x86_64-linux]

安装目录：/usr/local/share/ruby/gems/2.0

RUBY 可执行文件：/usr/bin/ruby2.0

可执行目录：/usr/local/bin

RUBYGEMS 平台：

红宝石

x86_64-linux

宝石路径：

/usr/local/share/ruby/gems/2.0

/root/.gem/ruby/2.0

/usr/share/ruby/gems/2.0

宝石配置：

:update_sources => 真

:verbose => 真

:回溯 => 假

:bulk_threshold => 1000

远程源：

https://rubygems.org/

如果我这样做：

ls -al /usr/local/share/ruby/gems/2.0/gems/io-console-0.4.2/

我看到 gem 已安装。

为什么会收到 LoadError？

如果我这样做：

emacs /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb

并像这样编辑此方法：

def require(file)

result = false

print file

print " \n\n "

load_dependency(file) { result = super }

result

end

然后我再试一次：

rails 生成控制器欢迎索引

然后我明白了：

active_support/descendants_tracker

导轨/引擎/导轨

active_support/core_ext/module/delegation

active_support/core_ext/object/to_param

active_support/core_ext/regexp

旅程

旅程/路由器

旅程/核心扩展/哈希

旅程/路由器/实用程序

uri

旅程/路由器/strexp

旅程/路线

旅程/格式化程序

旅程/解析器

racc/parser.rb

racc/cparse

旅程/parser_extras

旅程/扫描仪

strscan

旅程/节点/节点

旅程/访客

旅程/路线

旅程/路径/模式

旅程/gtg/建造者

旅程/gtg/transition_table

旅程/nfa/点

旅程/gtg/模拟器

strscan

旅程/nfa/建造者

旅程/nfa/transition_table

旅程/nfa/点

旅程/gtg/transition_table

旅程/nfa/模拟器

strscan

可转发

active_support/core_ext/object/blank

active_support/core_ext/object/to_query

active_support/core_ext/object/to_param

active_support/core_ext/hash/slice

active_support/core_ext/module/remove_method

action_controller/metal/exceptions

临时文件

字符串

strscan

active_support/core_ext/hash/indifferent_access

active_support/hash_with_indifferent_access

active_support/core_ext/hash/keys

active_support/core_ext/string/access

active_support/多字节

active_support/变形器

action_dispatch/http/headers

action_controller/metal/exceptions

机架/工具

文件工具

设置

临时文件

机架/多部分

uri/common

active_support/core_ext/object/blank

active_support/core_ext/hash/keys

active_support/core_ext/hash/indifferent_access

active_support/core_ext/object/blank

active_support/core_ext/hash/keys

active_support/core_ext/object/可复制

大数

/home/ec2-user/oscar/config/environments/development.rb

active_support/全部

主动支持

active_support/时间

主动支持

日期

时间

active_support/core_ext/time/publicize_conversion_methods

active_support/core_ext/time/marshal

active_support/core_ext/time/acts_like

active_support/core_ext/object/acts_like

active_support/core_ext/时间/计算

active_support/core_ext/time/conversions

active_support/core_ext/time/zones

active_support/core_ext/date/acts_like

active_support/core_ext/object/acts_like

active_support/core_ext/date/freeze

active_support/core_ext/日期/计算

active_support/core_ext/date/conversions

日期

active_support/inflector/methods

active_support/core_ext/date/zones

active_support/core_ext/module/remove_method

active_support/core_ext/date/zones

active_support/core_ext/date_time/acts_like

日期

active_support/core_ext/object/acts_like

active_support/core_ext/date_time/计算

active_support/core_ext/date_time/conversions

active_support/core_ext/date_time/zones

active_support/core_ext/time/zones

active_support/core_ext/整数/时间

active_support/core_ext/numeric/time

active_support/持续时间

active_support/core_ext/时间/计算

active_support/core_ext/time/acts_like

active_support/core_ext

active_support/core_ext/array

active_support/core_ext/array/wrap

active_support/core_ext/array/access

active_support/core_ext/array/uniq_by

active_support/core_ext/array/conversions

active_support/core_ext/array/extract_options

active_support/core_ext/array/分组

枚举器

active_support/core_ext/array/random_access

active_support/core_ext/array/prepend_and_append

active_support/core_ext/benchmark

active_support/core_ext/big_decimal

active_support/core_ext/big_decimal/conversions

active_support/core_ext/class

active_support/core_ext/enumerable

active_support/core_ext/异常

active_support/core_ext/文件

active_support/core_ext/file/atomic

active_support/core_ext/文件/路径

active_support/core_ext/float

active_support/core_ext/float/rounding

active_support/core_ext/hash

active_support/core_ext/hash/conversions

active_support/xml_mini

active_support/时间

active_support/core_ext/array/wrap

active_support/core_ext/hash/reverse_merge

active_support/core_ext/object/blank

active_support/core_ext/string/inflections

active_support/core_ext/hash/deep_merge

active_support/core_ext/hash/deep_dup

active_support/core_ext/hash/diff

active_support/core_ext/hash/except

active_support/core_ext/hash/indifferent_access

active_support/core_ext/hash/keys

active_support/core_ext/hash/reverse_merge

active_support/core_ext/hash/slice

active_support/core_ext/整数

active_support/core_ext/integer/multiple

active_support/core_ext/integer/inflections

active_support/变形器

active_support/core_ext/整数/时间

active_support/core_ext/io

active_support/core_ext/内核

active_support/core_ext/kernel/reporting

active_support/core_ext/kernel/agnostics

active_support/core_ext/内核/调试器

active_support/core_ext/kernel/singleton_class

active_support/core_ext/load_error

active_support/core_ext/logger

active_support/core_ext/模块

active_support/core_ext/module/aliasing

active_support/core_ext/module/introspection

active_support/core_ext/module/匿名

active_support/core_ext/module/可达

active_support/core_ext/module/attribute_accessors

active_support/core_ext/module/attr_internal

active_support/core_ext/module/delegation

active_support/core_ext/模块/同步

线程

active_support/core_ext/module/aliasing

active_support/core_ext/array/extract_options

active_support/core_ext/module/deprecation

active_support/core_ext/module/deprecation

active_support/core_ext/module/remove_method

active_support/core_ext/module/method_names

active_support/core_ext/module/qualified_const

active_support/core_ext/name_error

active_support/core_ext/数字

active_support/core_ext/numeric/bytes

active_support/core_ext/numeric/time

active_support/core_ext/object

active_support/core_ext/object/acts_like

active_support/core_ext/object/blank

active_support/core_ext/object/可复制

active_support/core_ext/object/try

active_support/core_ext/object/inclusion

active_support/core_ext/object/conversions

active_support/core_ext/object/to_param

active_support/core_ext/object/to_query

active_support/core_ext/array/conversions

active_support/core_ext/hash/conversions

active_support/core_ext/object/instance_variables

active_support/core_ext/object/to_json

json

active_support/core_ext/object/to_param

active_support/core_ext/object/to_query

active_support/core_ext/object/with_options

active_support/option_merger

active_support/core_ext/hash/deep_merge

active_support/core_ext/proc

active_support/core_ext/kernel/singleton_class

active_support/core_ext/进程

active_support/core_ext/进程/守护进程

active_support/core_ext/范围

active_support/core_ext/range/blockless_step

active_support/core_ext/module/aliasing

active_support/core_ext/range/conversions

active_support/core_ext/range/include_range

active_support/core_ext/range/overlaps

active_support/core_ext/range/cover

active_support/core_ext/regexp

active_support/core_ext/rexml

active_support/core_ext/string

active_support/core_ext/string/conversions

active_support/core_ext/string/filters

active_support/core_ext/字符串/多字节

active_support/core_ext/字符串/多字节

active_support/core_ext/string/starts_ends_with

active_support/core_ext/string/inflections

active_support/core_ext/string/access

active_support/core_ext/string/xchar

fast_xs

active_support/core_ext/字符串/行为

active_support/core_ext/string/interpolation

active_support/core_ext/string/output_safety

active_support/core_ext/string/排除

active_support/core_ext/字符串/编码

active_support/core_ext/string/strip

active_support/core_ext/object/try

active_support/core_ext/string/inquiry

active_support/string_inquirer

active_support/core_ext/uri

active_support/core_ext/object/blank

active_support/deprecation

记录器

线程

记录器

active_support/core_ext/logger

active_support/core_ext/class/attribute_accessors

active_support/deprecation

文件工具

基准测试

zlib

active_support/core_ext/array/extract_options

active_support/core_ext/array/wrap

active_support/core_ext/benchmark

active_support/core_ext/异常

active_support/core_ext/class/attribute_accessors

active_support/core_ext/numeric/bytes

active_support/core_ext/numeric/time

active_support/core_ext/object/to_param

active_support/core_ext/string/inflections

active_support/cache/file_store

active_support/core_ext/file/atomic

active_support/core_ext/string/conversions

active_support/core_ext/object/inclusion

机架/工具

active_support/core_ext/object/可复制

active_support/core_ext/string/inflections

萨斯

sass/版本

日期

sass/实用程序

erb

设置

枚举器

字符串

rbconfig

uri

线程

路径名

sass/根

sass/util/subset_map

设置

sass/util/multibyte_string_scanner

strscan

sass/util/normalized_map

委托

sass/实用程序

sass/util/cross_platform_random

sass/记录器

sass/实用程序

sass/引擎

设置

摘要/sha1

sass/cache_stores

字符串

sass/cache_stores/base

sass/cache_stores/文件系统

文件工具

sass/cache_stores/内存

sass/cache_stores/链

sass/来源/位置

sass/来源/范围

sass/源/地图

sass/树/节点

sass/tree/root_node

sass/tree/rule_node

路径名

sass/tree/comment_node

sass/树/节点

sass/tree/prop_node

sass/tree/directive_node

sass/tree/media_node

sass/tree/supports_node

sass/tree/css_import_node

sass/tree/variable_node

sass/tree/mixin_def_node

sass/tree/mixin_node

sass/树/节点

sass/tree/trace_node

sass/树/节点

sass/tree/content_node

sass/tree/function_node

sass/tree/return_node

sass/tree/extend_node

sass/树/节点

sass/tree/if_node

sass/树/节点

sass/tree/while_node

sass/树/节点

sass/tree/for_node

sass/树/节点

sass/tree/each_node

sass/树/节点

sass/tree/debug_node

sass/tree/warn_node

sass/tree/import_node

sass/tree/charset_node

sass/tree/at_root_node

sass/tree/visitors/base

sass/树/访问者/执行

sass/tree/visitors/cssize

sass/树/访问者/扩展

sass/tree/visitors/convert

sass/tree/visitors/to_css

sass/tree/visitors/deep_copy

sass/tree/visitors/set_options

sass/tree/visitors/check_nesting

sass/选择器

sass/选择器/简单

sass/selector/abstract_sequence

sass/selector/comma_sequence

sass/选择器/序列

sass/selector/simple_sequence

sass/环境

设置

sass/脚本

sass/scss/rx

sass/脚本/函数

sass/脚本/值/助手

sass/脚本/解析器

sass/脚本/词法分析器

sass/scss/rx

sass/脚本/树

sass/脚本/树/节点

sass/脚本/树/变量

sass/脚本/树/funcall

sass/脚本/函数

sass/util/normalized_map

sass/脚本/树/操作

sass/script/tree/unary_operation

sass/脚本/树/插值

sass/script/tree/string_interpolation

sass/脚本/树/字面量

sass/script/tree/list_literal

sass/script/tree/map_literal

sass/脚本/值

sass/脚本/值/基础

sass/脚本/值/字符串

sass/脚本/值/数字

sass/脚本/值/颜色

sass/脚本/值/布尔值

sass/script/value/deprecated_false

sass/脚本/值/null

sass/脚本/值/列表

sass/脚本/值/arg_list

sass/脚本/值/映射

sass/scss

sass/scss/rx

sass/scss/script_lexer

sass/scss/script_parser

sass/scss/解析器

设置

sass/scss/static_parser

sass/script/css_parser

sass/脚本

sass/script/css_lexer

sass/scss/css_parser

sass/script/css_parser

sass/堆栈

sass/错误

sass/进口商

sass/进口商/基地

sass/importers/文件系统

设置

sass/importers/deprecated_pa​​th

sass/共享

sass/媒体

sass/支持

sass/railtie

sass/功能

设置

链轮

链轮/版本

链轮/eco_template

倾斜

倾斜/字符串

倾斜/模板

倾斜/erb

倾斜/模板

倾斜/etanni

倾斜/模板

倾斜/haml

倾斜/模板

倾斜/css

倾斜/模板

倾斜/csv

倾斜/模板

倾斜/咖啡

倾斜/模板

倾斜/nokogiri

倾斜/模板

倾斜/建造者

倾斜/模板

倾斜/标记

倾斜/模板

倾斜/液体

倾斜/模板

倾斜/半径

倾斜/模板

倾斜/降价

倾斜/模板

倾斜/纺织

倾斜/模板

倾斜/rdoc

倾斜/模板

倾斜/维基

倾斜/模板

倾斜/yajl

倾斜/模板

倾斜/asciidoc

倾斜/模板

倾斜/平面

倾斜/模板

链轮/ejs_template

倾斜

链轮/jst_processor

倾斜

链轮/工具

倾斜

倾斜

链轮

action_dispatch/middleware/body_proxy

active_support/whiny_nil

active_support/deprecation

active_support/core_ext/time/zones

知乎

tzinfo/ruby_core_support

日期

tzinfo/offset_rationals

tzinfo/time_or_datetime

日期

时间

tzinfo/timezone_definition

tzinfo/timezone_offset_info

tzinfo/timezone_transition_info

日期

tzinfo/timezone_index_definition

tzinfo/timezone_info

tzinfo/data_timezone_info

tzinfo/linked_timezone_info

tzinfo/timezone_period

tzinfo/时区

日期

tzinfo/info_timezone

tzinfo/data_timezone

tzinfo/linked_timezone

tzinfo/timezone_proxy

tzinfo/country_index_definition

tzinfo/country_info

tzinfo/国家/地区

tzinfo/country_timezone

摘要/md5

active_support/core_ext/module/delegation

active_support/core_ext/object/blank

active_support/core_ext/class/attribute_accessors

机架/请求

机架/工具

时间

action_controller/metal/exceptions

active_support/core_ext/异常

active_support/core_ext/object/blank

active_support/core_ext/hash/keys

active_support/core_ext/module/attribute_accessors

active_record/railties/controller_runtime

active_support/core_ext/module/attr_internal

active_record/log_subscriber

active_support/core_ext/module/attribute_accessors

active_support/core_ext/类/属性

链轮

链轮/底座

链轮/资产属性

路径名

链轮/捆绑资产

链轮/资产

时间

设置

链轮/错误

文件工具

设置

zlib

链轮/缓存

sprockets/processed_asset

链轮/资产

链轮/工具

链轮/加工

链轮/引擎

链轮/mime

机架/mime

链轮/处理器

倾斜

链轮/工具

链轮/服务器

时间

uri

链轮/静态资产

链轮/资产

文件工具

zlib

链轮/轨迹

链轮/错误

路径名

路径名

链轮/charset_normalizer

倾斜

链轮/上下文

base64

机架/工具

链轮/错误

链轮/工具

路径名

设置

链轮/directive_processor

路径名

关键词

倾斜

yaml

链轮/索引

链轮/底座

链轮/安全冒号

倾斜

远足

记录器

路径名

倾斜

路径名

远足/扩展

hike/normalized_array

远足/索引

路径名

远足/路径

路径名

hike/normalized_array

摘要/md5

active_support/cache/file_store

action_controller/railtie

active_support/inflector/methods

active_support/依赖项

机架/工具

线程

机架/body_proxy

安全随机

active_support/core_ext/string/access

active_support/core_ext/object/blank

active_support/core_ext/time/conversions

active_support/core_ext/object/blank

action_dispatch/http/request

action_dispatch/middleware/exception_wrapper

active_support/deprecation

action_dispatch/http/request

action_dispatch/middleware/exception_wrapper

active_support/core_ext/module/delegation

active_support/core_ext/hash/keys

active_support/core_ext/object/blank

action_dispatch/middleware/session/abstract_store

机架/工具

机架/请求

机架/会话/抽象/id

时间

机架/请求

机架/响应

安全随机

action_dispatch/中间件/cookies

active_support/core_ext/object/blank

机架/会话/cookie

openssl

机架/请求

机架/响应

机架/会话/抽象/id

active_support/core_ext/hash/conversions

action_dispatch/http/request

active_support/core_ext/hash/indifferent_access

设置

active_support/core_ext/class/attribute_accessors

active_support/core_ext/object/blank

action_dispatch/http/mime_types

机架/工具

摘要/md5

active_support/core_ext/object/blank

线程

监控

设置

active_support/core_ext/module/deprecation

时间

机架/工具

机架/mime

yaml

i18n/core_ext/哈希

i18n/core_ext/kernel/surpress_warnings

active_support/core_ext/hash/except

active_support/core_ext/object/blank

active_support/core_ext/object/inclusion

active_support/core_ext/enumerable

active_support/变形器

action_dispatch/路由/重定向

action_dispatch/http/request

active_support/core_ext/uri

机架/工具

导轨/发电机

导轨/发电机

导轨/发电机

rails/命令/生成

导轨/发电机

active_support/core_ext/object/inclusion

rails/generators/controller/controller/controller_generator

发电机/控制器/控制器/controller_generator

rails/generators/controller/controller_generator

发电机/控制器/controller_generator

rails/generators/rails/controller/controller_generator

active_support/core_ext/module/introspection

rails/generators/base

rails/generators/generated_attribute

active_support/时间

active_support/core_ext/object/inclusion

active_support/core_ext/object/blank

雷神/外壳/基本

临时文件

io/控制台

然后我得到错误：

/usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:253:in `require': 无法加载这样的文件 -- io/console (LoadError )

我注意到大多数 gem 都有一个以 gem 命名的文件。例如，多边形有“polygon.rb”：

ls -al /usr/local/share/ruby/gems/2.0/gems/polyglot-0.3.4/lib/polyglot.rb

-rw-r--r-- 1 root root 2121 Apr 17 15:13 /usr/local/share/ruby/gems/2.0/gems/polyglot-0.3.4/lib/polyglot.rb

sass 有“sass.rb”：

[root@ip-172-31-38-140 奥斯卡]# ls -al /usr/local/share/ruby/gems/2.0/gems/sass-3.3.5/lib/sass.rb

-rw-r--r-- 1 root root 4188 Apr 17 15:23 /usr/local/share/ruby/gems/2.0/gems/sass-3.3.5/lib/sass.rb

但不是 io 控制台：

[root@ip-172-31-38-140 奥斯卡]# ls -al /usr/local/share/ruby/gems/2.0/gems/io-console-0.4.2/lib/

drwxr-xr-x 3 root root 4096 Apr 17 15:44 .

drwxr-xr-x 3 root root 4096 Apr 17 15:44 ..

drwxr-xr-x 2 root root 4096 Apr 17 15:44 控制台

[root@ip-172-31-38-140 oscar]# ls -al /usr/local/share/ruby/gems/2.0/gems/io-console-0.4.2/lib/console/

drwxr-xr-x 2 root root 4096 Apr 17 15:44 .

drwxr-xr-x 3 root root 4096 Apr 17 15:44 ..

-rw-r--r-- 1 根根 331 Apr 17 15:44 size.rb

我看到了这个文件：

/usr/local/share/ruby/gems/2.0/gems/io-console-0.4.2/console.so

所以我尝试了：

ln -s /usr/local/share/ruby/gems/2.0/gems/io-console-0.4.2/console.so /usr/share/ruby/gems/2.0/console

但这没有任何作用。我仍然得到同样的错误。

完整的堆栈跟踪：

rails 生成控制器欢迎索引

/usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:251:in `require': 无法加载此类文件 -- io/console (LoadError )

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:251:in `block in require'

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:236:in `load_dependency'

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:251:in `require'

from /usr/local/share/ruby/gems/2.0/gems/thor-0.19.1/lib/thor/shell/basic.rb:2:in `<top (required)>'

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:251:in `require'

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:251:in `block in require'

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:236:in `load_dependency'

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:251:in `require'

from /usr/local/share/ruby/gems/2.0/gems/thor-0.19.1/lib/thor/shell/color.rb:1:in `<top (required)>'

from /usr/local/share/ruby/gems/2.0/gems/thor-0.19.1/lib/thor/shell.rb:17:in `shell'

from /usr/local/share/ruby/gems/2.0/gems/thor-0.19.1/lib/thor/base.rb:439:in `start'

from /usr/local/share/ruby/gems/2.0/gems/railties-3.2.17/lib/rails/generators.rb:171:in `invoke'

from /usr/local/share/ruby/gems/2.0/gems/railties-3.2.17/lib/rails/commands/generate.rb:12:in `<top (required)>'

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:251:in `require'

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:251:in `block in require'

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:236:in `load_dependency'

from /usr/local/share/ruby/gems/2.0/gems/activesupport-3.2.17/lib/active_support/dependencies.rb:251:in `require'

from /usr/local/share/ruby/gems/2.0/gems/railties-3.2.17/lib/rails/commands.rb:29:in `<top (required)>'

from script/rails:6:in `require'

from script/rails:6:in `<main>'

Answer 1

我必须在Gemfile 中添加以下行：

  gem 'io-console'

然后我跑了

bundle install 

而且效果很好！