我正在尝试在我的MAC上设置Rails，但是即使遇到同样问题的人提供的所有先前帮助，仍然会出现错误。
我使用rbenv下载了Ruby 2.4.1，现在我需要安装rails 4.2.1，但是我仍然遇到以下错误。
错误：安装导轨时出错： 错误：无法构建gem本机扩展。
Fetching actionview-4.2.1.gem
Fetching actionpack-4.2.1.gem
Fetching railties-4.2.1.gem
Fetching activejob-4.2.1.gem
Fetching actionmailer-4.2.1.gem
Fetching activemodel-4.2.1.gem
Fetching activerecord-4.2.1.gem
Fetching rails-4.2.1.gem
Building native extensions. This could take a while...
ERROR: Error installing rails:
ERROR: Failed to build gem native extension.
current directory: /Library/Ruby/Gems/2.3.0/gems/nokogiri-1.10.3/ext/nokogiri
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/bin/ruby -I /Library/Ruby/Site/2.3.0 -r ./siteconf20190527-36261-6oqyvd.rb extconf.rb
checking if the C compiler accepts -I /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/libxml2... 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 2.4.0
checking for iconv.h... yes
checking for gzdopen() in -lz... yes
checking for iconv... yes
************************************************************************
IMPORTANT NOTICE:
Building Nokogiri with a packaged version of libxml2-2.9.9
with the following patches applied:
- 0001-Revert-Do-not-URI-escape-in-server-side-includes.patch
- 0002-Remove-script-macro-support.patch
- 0003-Update-entities-to-remove-handling-of-ssi.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 libxml2-2.9.9.tar.gz into tmp/x86_64-apple-darwin17/ports/libxml2/2.9.9... OK
Running git apply with /Library/Ruby/Gems/2.3.0/gems/nokogiri-1.10.3/patches/libxml2/0001-Revert-Do-not-URI-escape-in-server-side-includes.patch... OK
Running git apply with /Library/Ruby/Gems/2.3.0/gems/nokogiri-1.10.3/patches/libxml2/0002-Remove-script-macro-support.patch... OK
Running git apply with /Library/Ruby/Gems/2.3.0/gems/nokogiri-1.10.3/patches/libxml2/0003-Update-entities-to-remove-handling-of-ssi.patch... OK
Running 'configure' for libxml2 2.9.9... OK
Running 'compile' for libxml2 2.9.9... ERROR, review '/Library/Ruby/Gems/2.3.0/gems/nokogiri-1.10.3/ext/nokogiri/tmp/x86_64 apple-darwin17/ports/libxml2/2.9.9/compile.log' to see what happened. Last lines are:
========================================================================
CC testdso.lo
CCLD testdso.la
CC xmllint.o
CCLD xmllint
ld: warning: The i386 architecture is deprecated for macOS (remove from the Xcode build setting: ARCHS)
ld: warning: ignoring file /usr/local/Cellar/xz/5.2.4/lib/liblzma.dylib, file was built for x86_64 which is not the architecture being linked (i386): /usr/local/Cellar/xz/5.2.4/lib/liblzma.dylib
Undefined symbols for architecture i386:
"_lzma_auto_decoder", referenced from:
_xz_head in libxml2.a(xzlib.o)
"_lzma_code", referenced from:
_xz_decomp in libxml2.a(xzlib.o)
"_lzma_end", referenced from:
___libxml2_xzclose in libxml2.a(xzlib.o)
"_lzma_properties_decode", referenced from:
_is_format_lzma in libxml2.a(xzlib.o)
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [xmllint] 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
--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=/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/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
/Library/Ruby/Gems/2.3.0/gems/mini_portile2-2.4.0/lib/mini_portile2/mini_portile.rb:402:in `block in execute': Failed to complete compile task (RuntimeError)
from /Library/Ruby/Gems/2.3.0/gems/mini_portile2-2.4.0/lib/mini_portile2/mini_portile.rb:373:in `chdir'
from /Library/Ruby/Gems/2.3.0/gems/mini_portile2-2.4.0/lib/mini_portile2/mini_portile.rb:373:in `execute'
from /Library/Ruby/Gems/2.3.0/gems/mini_portile2-2.4.0/lib/mini_portile2/mini_portile.rb:115:in `compile'
from /Library/Ruby/Gems/2.3.0/gems/mini_portile2-2.4.0/lib/mini_portile2/mini_portile.rb:154: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:557:in `<main>'
To see why this extension failed to compile, please check the mkmf.log which can be found here:
/Library/Ruby/Gems/2.3.0/extensions/universal-darwin-17/2.3.0/nokogiri-1.10.3/mkmf.log
extconf failed, exit code 1
Gem files will remain installed in /Library/Ruby/Gems/2.3.0/gems/nokogiri-1.10.3 for inspection.
Results logged to /Library/Ruby/Gems/2.3.0/extensions/universal-darwin-17/2.3.0/nokogiri-1.10.3/gem_make.out
我已经看到：
gem update --system 3.0.3
但是不需要，因为我已经有了最新版本的gem。
我尝试过：
sudo gem install rails --version 4.2.1
但这就是引发以上错误的原因。
答案 0 :(得分：2)
您遇到libxml2问题
确保已安装xcodebuild：
sudo xcodebuild -license accept
或尝试直接通过brew安装libxml2：
brew install libxml2
您也可以尝试运行
gem install nokogiri -v 1.10.3 -- --use-system-libraries
因为nokogiri附带了与某些系统不兼容的自己的libxml2