XQuartz not working on OS X El Capitan + Error 127 on OnyX

Yesterday my Inkscape installation was working ok. Now I used the computer and the XQuarz icon appears and closes immediately.

I tried to run the apps from terminal to see if there are warning messages

nb21:~ pacha$ open -a Inkscape
nb21:~ pacha$ open -a XQuartz

Have you faced the same? What can I do with no visible errors?

Today I tried running OnyX and I have two previously unseen errors: Error 127 sh: getconf: command not found and Error 127 sh: cat: command not found

I haven't installed new software or updates :S

my solution (I installed brew and xcode before)

brew install coreutils
brew install binutils
brew install diffutils
brew install ed --with-default-names
brew install findutils --with-default-names
brew install gawk
brew install gnu-indent --with-default-names
brew install gnu-sed --with-default-names
brew install gnu-tar --with-default-names
brew install gnu-which --with-default-names
brew install gnutls
brew install grep --with-default-names
brew install gzip
brew install screen
brew install watch
brew install wdiff --with-gettext
brew install wget
brew install bash
brew install emacs
brew install gdb
brew install gpatch
brew install less
brew install m4
brew install make
brew install nano
brew install file-formula
brew install git
brew install openssh
brew install perl
brew install python
brew install rsync
brew install svn
brew install unzip
brew install vim --override-system-vi
brew install macvim --override-system-vim --custom-system-icons
brew install zsh

sudo launchctl config user path /usr/local/opt/coreutils/libexec/gnuman:/usr/local/sbin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/Library/TeX/texbin