Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

Question

I can't install gem pg:
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
/home/alex/.rvm/rubies/ruby-2.1.1/bin/ruby extconf.rb
checking for pg_config... no
No pg_config... trying anyway. If building fails, please try again with
--with-pg-config=/path/to/pg_config
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header
*** 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:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/home/alex/.rvm/rubies/ruby-2.1.1/bin/ruby
--with-pg
--without-pg
--with-pg-config
--without-pg-config
--with-pg_config
--without-pg_config
--with-pg-dir
--without-pg-dir
--with-pg-include
--without-pg-include=${pg-dir}/include
--with-pg-lib
--without-pg-lib=${pg-dir}/lib
extconf failed, exit code 1
Gem files will remain installed in /home/alex/.rvm/gems/ruby-2.1.1/gems/pg-0.17.1 for inspection.
Results logged to /home/alex/.rvm/gems/ruby-2.1.1/extensions/x86_64-linux/2.1.0/pg-0.17.1/gem_make.out
In Ubuntu I can do this
$ sudo apt-get install ruby-dev build-essential
and it will the same issue. But in Arch I can't because these don't exist.
I also have libmariadbclient installed.

Answer 1

You can do:
Step1: You choose "Tools" -> Library Manager -> J2ME Ant Extension
Step2: in tab Classpath, you remove "C:\Program Files\netbeans-5.5\mobility7.3\modules\org-netbeans-modules-kjava-antext.jar"
Step3: You add again "C:\Program Files\netbeans-5.5\mobility7.3\modules\org-netbeans-modules-kjava-antext.jar"
Step4: Then you build your application again.
It'll build normally.
I tried.