cpan[1]> install Math::GSL
Going to read '/root/.cpan/Metadata'
  Database was generated on Fri, 04 Mar 2011 10:27:20 GMT
Running install for module 'Math::GSL'
Running make for L/LE/LETO/Math-GSL-0.22.tar.gz
Checksum for /root/.cpan/sources/authors/id/L/LE/LETO/Math-GSL-0.22.tar.gz ok
Scanning cache /root/.cpan/build for sizes
............................................................................DONE

  CPAN.pm: Going to build L/LE/LETO/Math-GSL-0.22.tar.gz

Checking for GSL..Package gsl was not found in the pkg-config search path.
Perhaps you should add the directory containing `gsl.pc'
to the PKG_CONFIG_PATH environment variable
No package 'gsl' found
 at Build.PL line 108
*** can not find package gsl
*** check that it is properly installed and available in PKG_CONFIG_PATH
 at Build.PL line 108
Warning: No success on command[/usr/bin/perl Build.PL ]
'YAML' not installed, will not store persistent state
  LETO/Math-GSL-0.22.tar.gz
  /usr/bin/perl Build.PL  -- NOT OK
Running Build test
  Make had some problems, won't test
Running Build install
  Make had some problems, won't install
Could not read '/root/.cpan/build/Math-GSL-0.22-pXritF/META.yml'. Falling back to other methods to determine prerequisites
Failed during this command:
 LETO/Math-GSL-0.22.tar.gz                    : writemakefile NO '/usr/bin/perl Build.PL ' returned status 256