Rails 5 Installation Woes

I ran into issues installing Rails 5 today. It was blowing up trying to install the Nokogiri gem. The full error message is at the bottom of this post, if you’re curious (and for the benefit of SEO).

The fix was to install the Xcode Command Line tools. This, despite the fact that I have the latest version of Xcode installed. So after running:

$ xcode-select --install

I could run gem install rails without issue. Weird.

FWIW, I’m running OS X 10.11.5 and Ruby 2.3.1 installed via rbenv.

Full output of the errors thrown when trying to install Nokogiri:

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

    current directory: /Users/erikhansen/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/nokogiri-1.6.8/ext/nokogiri
/Users/erikhansen/.rbenv/versions/2.3.1/bin/ruby -r ./siteconf20160703-99836-186h6s0.rb extconf.rb
Using pkg-config version 1.1.7
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 2.1.0
checking for iconv.h... yes
checking for gzdopen() in -lz... yes
checking for iconv... yes

Building Nokogiri with a packaged version of libxml2-2.9.4.

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

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-darwin15.5.0/ports/libxml2/2.9.4... OK
Running 'configure' for libxml2 2.9.4... OK
Running 'compile' for libxml2 2.9.4... ERROR, review '/Users/erikhansen/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/nokogiri-1.6.8/ext/nokogiri/tmp/x86_64-apple-darwin15.5.0/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:
/Users/erikhansen/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mini_portile2-2.1.0/lib/mini_portile2/mini_portile.rb:366:in `block in execute': Failed to complete compile task (RuntimeError)
    from /Users/erikhansen/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mini_portile2-2.1.0/lib/mini_portile2/mini_portile.rb:337:in `chdir'
    from /Users/erikhansen/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mini_portile2-2.1.0/lib/mini_portile2/mini_portile.rb:337:in `execute'
    from /Users/erikhansen/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mini_portile2-2.1.0/lib/mini_portile2/mini_portile.rb:111:in `compile'
    from /Users/erikhansen/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/mini_portile2-2.1.0/lib/mini_portile2/mini_portile.rb:150:in `cook'
    from extconf.rb:364: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:363:in `block in process_recipe'
    from extconf.rb:262:in `tap'
    from extconf.rb:262:in `process_recipe'
    from extconf.rb:555:in `<main>'

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


extconf failed, exit code 1

Gem files will remain installed in /Users/erikhansen/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/nokogiri-1.6.8 for inspection.
Results logged to /Users/erikhansen/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/extensions/x86_64-darwin-15/2.3.0-static/nokogiri-1.6.8/gem_make.out