Fail to install pg gem in Rails (using PostgreSQL 9.6) - ruby-on-rails

Question

Hi could someone please help me! Appreciate it a lot!
I have some problem bundle install because the terminal says I fail to install gem pg v 0.20.0
When I tried to install the gem pg this error occurs. I'm currently using PostgreSQL 9.6 I have tried through all the solutions in the similar question but nothing works, including trying to reconfigure pg.
198-195:Review minhvu$ gem install pg -- --with-pg-config=/usr/pgsql-9.6/bin/pg_config
Building native extensions with: '--with-pg-config=/usr/pgsql-9.6/bin/pg_config'
This could take a while...
ERROR: Error installing pg:
ERROR: Failed to build gem native extension.
current directory: /Users/minhvu/.rvm/gems/ruby-2.3.0/gems/pg-0.20.0/ext
/Users/minhvu/.rvm/rubies/ruby-2.3.0/bin/ruby -r ./siteconf20170313-7016-1if947v.rb extconf.rb --with-pg-config=/usr/pgsql-9.6/bin/pg_config
Using config values from /usr/pgsql-9.6/bin/pg_config
sh: /usr/pgsql-9.6/bin/pg_config: No such file or directory
sh: /usr/pgsql-9.6/bin/pg_config: No such file or directory
* 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
--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=/Users/minhvu/.rvm/rubies/ruby-2.3.0/bin/$(RUBY_BASE_NAME)
--with-pg
--without-pg
--enable-windows-cross
--disable-windows-cross
--with-pg-config
--with-pg-dir
--without-pg-dir
--with-pg-include
--without-pg-include=${pg-dir}/include
--with-pg-lib
--without-pg-lib=${pg-dir}/lib
/Users/minhvu/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/mkmf.rb:456:in try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /Users/minhvu/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/mkmf.rb:541:intry_link0'
from /Users/minhvu/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/mkmf.rb:556:in try_link'
from extconf.rb:40:in'
To see why this extension failed to compile, please check the mkmf.log which can be found here:
/Users/minhvu/.rvm/gems/ruby-2.3.0/extensions/x86_64-darwin-16/2.3.0/pg-0.20.0/mkmf.log
extconf failed, exit code 1
Gem files will remain installed in /Users/minhvu/.rvm/gems/ruby-2.3.0/gems/pg-0.20.0 for inspection.
Results logged to /Users/minhvu/.rvm/gems/ruby-2.3.0/extensions/x86_64-darwin-16/2.3.0/pg-0.20.0/gem_make.out

Answer 1

It seems to me, that you are trying to installing pg gem, but first you should install PostgreSQL in your system. Depending of what system you have you should follow the instructions in this post. I am quoting the answer from addicted Addicted user at the following post
Rails Error Installing PG
Steps to install
Install PostgreSQL and its libraries
sudo apt-get install postgresql postgresql-contrib libpq-dev
After the installation create a user for postgresql
sudo -u postgres createuser --superuser $USER
or
sudo -u postgres createuser pgs_root
Set user password for the postgresql user
sudo -u postgres psql postgres ( For psql prompt) postgres=# \passsword for ex.- postgres=# \passsword pgs_root
Configure the postgresql.conf file to make PostgreSQL listen to localhost or listen on an external IP or something, change this line to either the IP or 'localhost'
gedit /etc/postgresql/8.4/main/postgresql.conf listen_addresses = 'localhost