我尝试使用以下方法在我的系统上安装Rails：
gem install rails
但我收到了这个错误：
Sams-MacBook-Pro-2:/ sammy$ gem install rails
Building native extensions. This could take a while...
ERROR: Error installing rails:
ERROR: Failed to build gem native extension.
current directory: /Users/sammy/.rvm/gems/ruby-2.4.1/gems/nokogiri-1.8.0/ext/nokogiri
/Users/sammy/.rvm/rubies/ruby-2.4.1/bin/ruby -r ./siteconf20170716-20185-7bepnp.rb extconf.rb
checking if the C compiler accepts ... yes
checking if the C compiler accepts -Wno-error=unused-command-line-argument-hard-error-in-future... no
Building nokogiri using packaged libraries.
Using mini_portile version 2.2.0
checking for iconv.h... yes
checking for gzdopen() in -lz... yes
checking for iconv using --with-opt-* flags... yes
************************************************************************
IMPORTANT NOTICE:
Building Nokogiri with a packaged version of libxml2-2.9.4
with the following patches applied:
- 0001-Fix-comparison-with-root-node-in-xmlXPathCmpNodes.patch
- 0002-Fix-XPointer-paths-beginning-with-range-to.patch
- 0003-Disallow-namespace-nodes-in-XPointer-ranges.patch
Team Nokogiri will keep on doing their best to provide security
updates in a timely manner, but if this is a concern for you and want
to use the system library instead; abort this installation process and
reinstall nokogiri as follows:
gem install nokogiri -- --use-system-libraries
[--with-xml2-config=/path/to/xml2-config]
[--with-xslt-config=/path/to/xslt-config]
If you are using Bundler, tell it to use the option:
bundle config build.nokogiri --use-system-libraries
bundle install
Note, however, that nokogiri is not fully compatible with arbitrary
versions of libxml2 provided by OS/package vendors.
************************************************************************
Extracting libxml2-2.9.4.tar.gz into tmp/x86_64-apple-darwin16.0.0/ports/libxml2/2.9.4... OK
Running git apply with /Users/sammy/.rvm/gems/ruby-2.4.1/gems/nokogiri-1.8.0/patches/libxml2/0001-Fix-comparison-with-root-node-in-xmlXPathCmpNodes.patch... OK
Running git apply with /Users/sammy/.rvm/gems/ruby-2.4.1/gems/nokogiri-1.8.0/patches/libxml2/0002-Fix-XPointer-paths-beginning-with-range-to.patch... OK
Running git apply with /Users/sammy/.rvm/gems/ruby-2.4.1/gems/nokogiri-1.8.0/patches/libxml2/0003-Disallow-namespace-nodes-in-XPointer-ranges.patch... OK
Running 'configure' for libxml2 2.9.4... OK
Running 'compile' for libxml2 2.9.4... ERROR, review '/Users/sammy/.rvm/gems/ruby-2.4.1/gems/nokogiri-1.8.0/ext/nokogiri/tmp/x86_64-apple-darwin16.0.0/ports/libxml2/2.9.4/compile.log' to see what happened. Last lines are:
========================================================================
unsigned short* in = (unsigned short*) inb;
^~~~~~~~~~~~~~~~~~~~~
encoding.c:815:27: warning: cast from 'unsigned char *' to 'unsigned short *' increases required alignment from 1 to 2 [-Wcast-align]
unsigned short* out = (unsigned short*) outb;
^~~~~~~~~~~~~~~~~~~~~~
4 warnings generated.
CC error.lo
CC parserInternals.lo
CC parser.lo
CC tree.lo
CC hash.lo
CC list.lo
CC xmlIO.lo
xmlIO.c:1450:52: error: use of undeclared identifier 'LZMA_OK'
ret = (__libxml2_xzclose((xzFile) context) == LZMA_OK ) ? 0 : -1;
^
1 error generated.
make[2]: *** [xmlIO.lo] Error 1
make[1]: *** [all-recursive] Error 1
make: *** [all] Error 2
========================================================================
*** 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
--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=/Users/sammy/.rvm/rubies/ruby-2.4.1/bin/$(RUBY_BASE_NAME)
--help
--clean
--use-system-libraries
--enable-static
--disable-static
--with-zlib-dir
--without-zlib-dir
--with-zlib-include
--without-zlib-include=${zlib-dir}/include
--with-zlib-lib
--without-zlib-lib=${zlib-dir}/lib
--enable-cross-build
--disable-cross-build
/Users/sammy/.rvm/rubies/ruby-2.4.1/lib/ruby/gems/2.4.0/gems/mini_portile2-2.2.0/lib/mini_portile2/mini_portile.rb:400:in `block in execute': Failed to complete compile task (RuntimeError)
from /Users/sammy/.rvm/rubies/ruby-2.4.1/lib/ruby/gems/2.4.0/gems/mini_portile2-2.2.0/lib/mini_portile2/mini_portile.rb:371:in `chdir'
from /Users/sammy/.rvm/rubies/ruby-2.4.1/lib/ruby/gems/2.4.0/gems/mini_portile2-2.2.0/lib/mini_portile2/mini_portile.rb:371:in `execute'
from /Users/sammy/.rvm/rubies/ruby-2.4.1/lib/ruby/gems/2.4.0/gems/mini_portile2-2.2.0/lib/mini_portile2/mini_portile.rb:114:in `compile'
from /Users/sammy/.rvm/rubies/ruby-2.4.1/lib/ruby/gems/2.4.0/gems/mini_portile2-2.2.0/lib/mini_portile2/mini_portile.rb:153:in `cook'
from extconf.rb:365:in `block (2 levels) in process_recipe'
from extconf.rb:257:in `block in chdir_for_build'
from extconf.rb:256:in `chdir'
from extconf.rb:256:in `chdir_for_build'
from extconf.rb:364:in `block in process_recipe'
from extconf.rb:262:in `tap'
from extconf.rb:262:in `process_recipe'
from extconf.rb:548:in `<main>'
To see why this extension failed to compile, please check the mkmf.log which can be found here:
/Users/sammy/.rvm/gems/ruby-2.4.1/extensions/x86_64-darwin-16/2.4.0/nokogiri-1.8.0/mkmf.log
extconf failed, exit code 1
Gem files will remain installed in /Users/sammy/.rvm/gems/ruby-2.4.1/gems/nokogiri-1.8.0 for inspection.
Results logged to /Users/sammy/.rvm/gems/ruby-2.4.1/extensions/x86_64-darwin-16/2.4.0/nokogiri-1.8.0/gem_make.out
我尝试使用以下方式卸载Nokogiri：
gem uninstall nokogiri
然后重新运行：
gem install rails
但我得到了同样的错误。
我甚至试图查找并删除包含＆＃34; nokogiri＆＃34;的所有目录。在其中，然后重新命令，得到相同的错误。
为什么Nokogiri不会离开？
答案 0 :(得分：0)
您的问题不是卸载Nokogiri，而是安装它。 Rails需要Nokogiri才能工作，但是你的系统可能缺少必需的库，这会阻止nokogiri的安装。您可能还在系统上安装了一个不稳定的库，但该扩展编译失败。
我根据您的错误日志快速搜索并发现此问题：https://github.com/sparklemotion/nokogiri/issues/1483但是，您遇到的问题可能相同或不同，但值得检查。
该问题的解决方案是卸载xz包。
brew uninstall xz
答案 1 :(得分：0)
请阅读Nokogiri安装教程，该教程明确解决您报告的问题：