how to solve "ruby installation is missing psych" error?

I used rvm to install ruby 1.9.3. even though it was successfully installed, it complained about libyaml. and now every time i wanna install a gem (say rails) this warning shows up:

It seems your ruby installation is missing psych (for YAML output). To eliminate this warning, please install libyaml and reinstall your ruby.

I use Mac os X 10.7 (Lion).

sudo port install libyaml # or brew install libyaml
rvm get latest
rvm pkg install iconv
rvm pkg install openssl
rvm reinstall 1.9.3 --with-openssl-dir=~/.rvm/usr --with-iconv-dir=~/.rvm/usr

curl -OL

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curl -OL

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gem install linecache19-0.5.13.gem ruby-debug-base19-0.11.26.gem -- --with-ruby-include=$rvm_path/src/ruby-1.9.3-p125/
gem install ruby-debug19

rvm reload

reload your .rvmrc (cd out, cd in)

bundle

for ubuntu and rvm

sudo apt-get install libtool
rvm pkg install libyaml
rvm reinstall 1.9.3

worked

brew install libyaml
rvm reinstall 1.9.3

Is what worked for me (on Snow Leopard).

On Snow Leopard, the solution by Catharz did not work for me. This solution, however, did:

brew install libyaml
rvm get head
rvm reinstall 1.9.3 --with-gcc=clang

(The rvm reinstall gave me a warning about clang not having the option "--with-libyaml" but it solved the error message regardless.)

I had the same problem (Lion 10.7.4), and fixed it by upgrading rvm then reinstalling ruby

1) upgrade rvm [

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][1]

curl -L

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| bash -s stable --ruby

2) Then use rvm to reinstall ruby 1.9.3 (which had been previously installed with the earlier version of rvm)

rvm reinstall 1.9.3

[1]:

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This worked for me at least on Ubuntu 10.04

$ sudo apt-get install libtool

$ rvm reinstall 1.9.3

In my case the solution was to add the `psych` gem to the Gemfile.

If not using rvm, but rather you are building and installing ruby 1.9.3 from scratch — for example, you're managing your ruby versions with [rbenv](

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) — you must install libyaml first. Get it from

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; at the moment, the file you want is

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. Open the tarball and cd into the resulting folder. Then:

./configure --prefix=/usr/local
make
sudo make install

You are now ready to build ruby. Download ruby from

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. Open the tarball and cd into the resulting folder. Now:

./configure --prefix=/wherever/you/want/it/to/go
make
make install

(Or possibly `sudo make install`, depending on where you're putting it.) If using rbenv, you'll know it has worked if you switch to `rbenv global 1.9.3-p194` (or whatever your version is called) and `gem --version` works without a warning. That worked for me on Mac OS X 10.6.8. (**Update**: I just tried this on Mac OS X 10.8.1 and it seems to have worked fine there too.)

None of these answers worked for me.

I found my answer on

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I am on Centos 6.3 Virtual Machine.

YOU MUST install libyaml before you install ruby. IF you ALREADY installed ruby you must get rid of the files before compiling source again!!!

# cd to your ruby source location
rm -rf /usr/local/lib/ruby # clean out ruby files
./configure
make && make install
gem -v # check if error is fixed