今天需要在由於工作需要，需要使用bundle install來更新依賴包，本以為很順利，結果遇到了下面的一堆問題，在此進行記錄並分享自己遇到這個問題時的思路：

問題一：用gem安裝ruby的包時出錯

root@kali:~/Desktop# gem install nokogiri -v ‘1.6.8.1‘

Building native extensions. This could take a while...
ERROR: Error installing nokogiri:
ERROR: Failed to build gem native extension.

current directory: /var/lib/gems/2.3.0/gems/nokogiri-1.6.8.1/ext/nokogiri
/usr/bin/ruby2.3 -r ./siteconf20171027-10596-epcpmc.rb extconf.rb
checking if the C compiler accepts ... yes
Building nokogiri using packaged libraries.
Using mini_portile version 2.1.0
checking for gzdopen() in -lz... no
zlib is missing; necessary for building libxml2
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary libraries and/or
headers. Check the mkmf.log file for more details. You may need configuration options.

Provided configuration options:
	--with-opt-dir
	--without-opt-dir
	--with-opt-include
	--without-opt-include=${opt-dir}/include
	--with-opt-lib
	--without-opt-lib=${opt-dir}/lib
	--with-make-prog
	--without-make-prog
	--srcdir=.
	--curdir
	--ruby=/usr/bin/$(RUBY_BASE_NAME)2.3
	--help
	--clean
	--use-system-libraries
	--enable-static
	--disable-static
	--with-zlib-dir
	--without-zlib-dir
	--with-zlib-include
	--without-zlib-include=${zlib-dir}/include
	--with-zlib-lib
	--without-zlib-lib=${zlib-dir}/lib
	--enable-cross-build
	--disable-cross-build

To see why this extension failed to compile, please check the mkmf.log which can be found
here:

/var/lib/gems/2.3.0/extensions/x86_64-linux/2.3.0/nokogiri-1.6.8.1/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /var/lib/gems/2.3.0/gems/nokogiri-1.6.8.1 for inspection.
Results logged to /var/lib/gems/2.3.0/extensions/x86_64-linux/2.3.0/nokogiri-1.6.8.1/gem_make.out

問題描述：

gem開始嘗試安裝，然後依次出現以下錯誤：
    1.安裝nokogiri失敗；
    2.構建gem本地拓展失敗；

然後，gem開始檢查為什麽失敗：
    1.checking if the C compiler accepts ... yes
    2.checking for gzdopen() in -lz... no

在這裏發現問題，於是gem給出失敗的原因：
    zlib is missing; necessary for building libxml2

所以說，問題的根據點在於如何安裝zlib。

思路：（系統為Linux）

1.直接啃錯誤信息，不要慫就是看。經過翻譯之後發現直接原因是gzdopen()函數沒有，這個函數沒有
是因為缺少了一個包：zlib，錯誤描述為：zlib is missing; necessary for building libxml2。根
據Linux的一貫作風，缺什麽裝什麽就行。
2.發現原因之後，可以直接去百度當前系統如何安裝zlib，但是，因為我有apt-get可以使用，於是，
直接上：apt-get install zlib加tag減，看一下都有哪些與zlib有關的可以直接安裝的東西，發現了4
個：zlib1g    zlib1g-dbg    zlib1g-dev    zlibc
因為我這裏需要調用zlib中的內容，本能的安裝開發者包：zliblg-dev：
apt-get install zliblg-dev


然後發現，問題被巧妙的解決了。

問題二：用gem安裝Ruby包又出錯了

root@kali:~/Desktop#  gem install pg -v ‘0.20.0‘

Building native extensions.  This could take a while...
ERROR:  Error installing pg:
ERROR: Failed to build gem native extension.

current directory: /var/lib/gems/2.3.0/gems/pg-0.20.0/ext
/usr/bin/ruby2.3 -r ./siteconf20171026-3597-1h17ktg.rb extconf.rb
checking for pg_config... yes
Using config values from /usr/bin/pg_config
You need to install postgresql-server-dev-X.Y for building a server-side extension or libpq-dev for building a client-side application.
You need to install postgresql-server-dev-X.Y for building a server-side extension or libpq-dev for building a client-side application.
checking for libpq-fe.h... no
Can‘t find the ‘libpq-fe.h header
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary libraries and/or 
headers.  Check the mkmf.log file for more details.  You may need configuration options.

Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/usr/bin/$(RUBY_BASE_NAME)2.3
    --with-pg
    --without-pg
    --enable-windows-cross
    --disable-windows-cross
    --with-pg-config
    --without-pg-config
    --with-pg_config
    --without-pg_config
    --with-pg-dir
    --without-pg-dir
    --with-pg-include
    --without-pg-include=${pg-dir}/include
    --with-pg-lib
    --without-pg-lib=${pg-dir}/lib

To see why this extension failed to compile, please check the mkmf.log which can be found here:

/var/lib/gems/2.3.0/extensions/x86_64-linux/2.3.0/pg-0.20.0/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /var/lib/gems/2.3.0/gems/pg-0.20.0 for inspection.
Results logged to /var/lib/gems/2.3.0/extensions/x86_64-linux/2.3.0/pg-0.20.0/gem_make.out

解決方案：(這裏的問題與上面的類似，於是先采用類似的方案嘗試解決。最終解決方案如下)

apt-get install libpq-dev

問題三：強大的gem

root@kali:~/Desktop#  gem install sqlite3 -v ‘1.3.13‘

Building native extensions.  This could take a while...
ERROR:  Error installing sqlite3:
ERROR: Failed to build gem native extension.

current directory: /var/lib/gems/2.3.0/gems/sqlite3-1.3.13/ext/sqlite3
/usr/bin/ruby2.3 -r ./siteconf20171026-6745-18q3rtn.rb extconf.rb
checking for sqlite3.h... no
sqlite3.h is missing. Try ‘brew install sqlite3‘,
‘yum install sqlite-devel‘ or ‘apt-get install libsqlite3-dev‘
and check your shared library search path (the
location where your sqlite3 shared library is located).
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
	--with-opt-dir
	--without-opt-dir
	--with-opt-include
	--without-opt-include=${opt-dir}/include
	--with-opt-lib
	--without-opt-lib=${opt-dir}/lib
	--with-make-prog
	--without-make-prog
	--srcdir=.
	--curdir
	--ruby=/usr/bin/$(RUBY_BASE_NAME)2.3
	--with-sqlite3-config
	--without-sqlite3-config
	--with-pkg-config
	--without-pkg-config
	--with-sqlite3-dir
	--without-sqlite3-dir
	--with-sqlite3-include
	--without-sqlite3-include=${sqlite3-dir}/include
	--with-sqlite3-lib
	--without-sqlite3-lib=${sqlite3-dir}/lib

To see why this extension failed to compile, please check the mkmf.log which can be found here:

/var/lib/gems/2.3.0/extensions/x86_64-linux/2.3.0/sqlite3-1.3.13/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /var/lib/gems/2.3.0/gems/sqlite3-1.3.13 for inspection.

解決方案：

這個例子中，有意思的地方在於gem不僅告訴你出現問題的原因，還給出了解決方案：
sqlite3.h is missing. Try ‘brew install sqlite3‘,‘yum install sqlite-devel‘ or ‘apt-get 
install libsqlite3-dev‘ and check your shared library search path (the location where your
 sqlite3 shared library is located).

這裏給我的經驗就是，一定要直接讀錯誤信息，一定要讀，一定要讀。

本文出自 “execute” 博客，請務必保留此出處http://executer.blog.51cto.com/10404661/1976896

gem安裝軟件時遇到的問題以及解決思路