安裝 nokogiri 失敗時的解決方法

(參考此篇文章)[https://github.com/sparklemotion/nokogiri/issues/1483] 在 bash 輸入 xcode-select --install 可解決問題。 在我的 macbook 上的錯誤訊息如下： ``` Gem::Ext::BuildError: ERROR: Failed to build gem native extension. current directory: /Users/etrex/.rvm/gems/ruby-2.4.1@-global/gems/nokogiri-1.8.0/ext/nokogiri /Users/etrex/.rvm/rubies/ruby-2.4.1/bin/ruby -r ./siteconf20171011-80748-pgpdll.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-darwin15.4.0/ports/libxml2/2.9.4... OK Running git apply with /Users/etrex/.rvm/gems/ruby-2.4.1@-global/gems/nokogiri-1.8.0/patches/libxml2/0001-Fix-comparison-with-root-node-in-xmlXPathCmpNodes.patch... OK Running git apply with /Users/etrex/.rvm/gems/ruby-2.4.1@-global/gems/nokogiri-1.8.0/patches/libxml2/0002-Fix-XPointer-paths-beginning-with-range-to.patch... OK Running git apply with /Users/etrex/.rvm/gems/ruby-2.4.1@-global/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/etrex/.rvm/gems/ruby-2.4.1@-global/gems/nokogiri-1.8.0/ext/nokogiri/tmp/x86_64-apple-darwin15.4.0/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. ```