Error while installing json gem 'mkmf.rb can&#

问题:

For context, it on a remote server which has a firewall. I'm setting up my environment through a proxy. I have ruby 1.8.7. When I try to gem install..

sudo gem install --http-proxy <host address>:<port> json

I get the following error:

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

/usr/bin/ruby extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/ruby.h

Gem files will remain installed in /usr/lib64/ruby/gems/1.8/gems/json-1.8.1 for inspection.
Results logged to /usr/lib64/ruby/gems/1.8/gems/json-1.8.1/ext/json/ext/generator/gem_make.out

Since I was unsure what the problem is, I googled and found these

• gem install: Failed to build gem native extension (can't find header files) - the instructions here seem to be specific to the gem being installed.

• How to install json gem - Failed to build gem native extension This seems to be slightly different error.

Any hints? Thanks!

回答1:

Modern era update, as stated by mimoralea:

In case that you are using ruby 2.0 or 2.2 (thanks @patrick-davey).

sudo apt-get install ruby-dev
sudo apt-get install ruby2.0-dev
sudo apt-get install ruby2.2-dev
sudo apt-get install ruby2.3-dev

or, generic way:

sudo apt-get install ruby`ruby -e 'puts RUBY_VERSION[/\d+\.\d+/]'`-dev

---

The first link you’ve posted is exactly your case: there is no ruby development environment installed. Development env is needed to compile ruby extensions, which are mostly written in C. Proxy has nothing to do with the problem: everything is downloaded fine, just compilation fails.

I would suggest you to install ruby-dev (ruby-devel for rpm-based distros) package onto you target machine. gcc package might be needed as well.

Try:

$ sudo apt-get install ruby-dev

Or, for Redhat distro:

$ sudo yum install ruby-devel

Or, for [open]SuSE:

$ sudo zypper install ruby-devel

回答2:

In case that you are using ruby 2.0 or 2.2 (thanks @patrick-davey) or 2.3 (thanks @juanitofatas).

sudo apt-get install ruby-dev
sudo apt-get install ruby2.0-dev
sudo apt-get install ruby2.2-dev
sudo apt-get install ruby2.3-dev

And you get the pattern here...

回答3:

I also encountered this problem because I install Ruby on Ubuntu via brightbox, and I thought ruby-dev is the trunk of ruby. So I did not install. Install ruby2.3-dev fixes it:

sudo apt-get install ruby2.3-dev

回答4:

For those who are getting this on Mac OS X you may need to run the following command to install the XCode command-line tools, even if you already have XCode installed:

sudo xcode-select --install

Also you must agree the terms and conditions of XCode by running the following command:

sudo xcodebuild -license

回答5:

I had a similar problem using cygwin to run the following command:

$ gem install rerun

I solved it by installing the following cygwin packages:

• ruby-devel
• libffi-devel
• gcc-core
• gcc-g++
• make
• automake1.15

回答6:

in case you use SUSE

sudo yast2 -i ruby-devel

回答7:

Most voted solution didn't work on my machine (linux mint 18.04). After a careful look, i found that g++ was missing. Solved with

sudo apt-get install g++

回答8:

In Fedora 21 and up, you simply open a terminal and install the Ruby Development files as root.

dnf install ruby-devel

回答9:

You may need to install gcc after install ruby-devel