unable to install pg gem

Question

I tried using gem install pg but it doesn't seem to work.

gem install pg gives this error

Temporarily enhancing PATH to include DevKit...
Building native extensions.  This could take a while...
ERROR:  Error installing pg:
        ERROR: Failed to build gem native extension.

C:/Ruby/bin/ruby.exe 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=C:/Ruby/bin/ruby
        --with-pg
        --without-pg
        --with-pg-dir
        --without-pg-dir
        --with-pg-include
        --without-pg-include=${pg-dir}/include
        --with-pg-lib
        --without-pg-lib=${pg-dir}/lib
        --with-pg-config
        --without-pg-config
        --with-pg_config
        --without-pg_config


Gem files will remain installed in C:/Ruby/lib/ruby/gems/1.8/gems/pg-0.10.1 for
inspection.
Results logged to C:/Ruby/lib/ruby/gems/1.8/gems/pg-0.10.1/ext/gem_make.out

in my case the error log said `libpq` was not found, so i installed `sudo apt install postgresql postgresql-contrib libpq-dev pgadmin3 -y` — Raj, Nov 27 '19 at 09:39
Try opening a new terminal tab and trying again. That worked for me. I had just installed psql, and the window I was trying to install the gem in didn't have psql in its path. — Jared Menard, Nov 10 '21 at 20:54

Devaroop · Answer 1 · 2015-03-20T06:57:30.177

436

I had this problem, this worked for me:

Install the postgresql-devel package, this will solve the issue of pg_config missing.

sudo apt-get install libpq-dev

edited Mar 20 '15 at 06:57

answered May 23 '11 at 10:09

Devaroop

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Worked for me by `apt-get install libpq-dev`. Thanks for the hint. – Ryanmt Jul 15 '11 at 17:09
and for me installing postgresql-server-dev-8.4 on ubuntu LTS 10 – mraaroncruz Sep 04 '11 at 22:56
5

Confirmation, from the [pg gem Wiki homepage](https://bitbucket.org/ged/ruby-pg/wiki/Home): "On Ubuntu, /usr/bin/pg_config is provided by the libpq-dev package." – Mark Berry Oct 05 '11 at 00:28
postgresql-devel doesn't exist for debian squeeze. We used postgresql-server-dev-8.4 and that worked. – dfrankow Feb 18 '12 at 00:58
Worked for me in openSUSE `zypper in postgresql-devel`. Fixed both the config & the libpq. – Hiasinho Nov 01 '12 at 16:47
Had the same issue on Fedora 17 this answer solved it (I used yum install postgres-devel). – Iain Nov 22 '12 at 04:47
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@Fivell Late to the game with the answer here, but if you have Homebrew installed, `brew install postgresql` will get you the packages you need. – Alex LaFroscia Dec 24 '14 at 16:33
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@Fivell try `brew install postgresql` on mac – Mahattam Jun 09 '15 at 17:39

score 110 · Answer 2 · edited Feb 24 '17 at 09:37

110

Issue is gem dependency so before installing pg make sure you have installed "libpq-dev"

Ubuntu systems:

sudo apt-get install libpq-dev

RHEL systems:

yum install postgresql-devel

Mac:

brew install postgresql

edited Feb 24 '17 at 09:37

umishra

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answered Jun 09 '15 at 09:53

Mahattam

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The answer for Mac is true. It's just because we haven't installed PostgreSQL on the machine. – Hoang Le Jun 09 '15 at 16:52
On Centos 7 `yum install postgresql-devel` solved my error related to pg_config for installing the 'pg' .gem. By the way I opted to use the just released PostgreSQL 10 – Arthur Nov 05 '17 at 02:42

score 69 · Answer 3 · answered Feb 10 '12 at 23:21

69

gem install pg -- --with-pg-config=/usr/pgsql-9.1/bin/pg_config

answered Feb 10 '12 at 23:21

Flaviu

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This helped me (on Centos 6.2) – TuK Sep 23 '12 at 16:47
14

Worked for me on OS X, but with path to /Applications/Postgres.app/Contents/MacOS/bin/pg_config (I have a standalone Postgres.app) – Matt Nov 15 '13 at 19:13
10

`gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.4/bin/pg_config ` on yosemite with Postgres App – skilleo Feb 11 '15 at 20:26
Worked. But on Mac, preceding with `env ARCHFLAGS="-arch x86_64"` was a game changer for me. – Janusz Lenar Mar 29 '16 at 12:38
Worked for me on OS X 10.11 with psql app 9.6 and gem version 0.18.4 `gem install pg -v '0.18.4' -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.6/bin/pg_config` – HarlemSquirrel Nov 15 '16 at 17:34
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I used `gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/latest/bin/pg_config` for OSX 10.12 – Tim Krins Nov 08 '17 at 18:26
This help me on OS X with no brew support (using postgres installer) – racar Feb 06 '20 at 03:39
macOS Monterey M1. Added to .zshrc `export PATH=$PATH:/Applications/Postgres.app/Contents/Versions/14/bin/` and `gem install pg` worked and could then `bundle install in Rails – Greg Jan 05 '22 at 01:45

score 46 · Answer 4 · edited May 23 '17 at 12:34

46

@Winfield said it:

The pg gem requires the postgresql client libraries to bind against. This error usually means it can't find your Postgres libraries. Either you don't have them installed or you may need to pass the --with-pg-dir= to your gem install.

More than that, you only need --with-pg-config= to install it.

On a Mac

If, by any chance, you also installed postgres through the website bundle on mac, it will be on somewhere like /Applications/Postgres.app/Contents/Versions/9.3/bin.

So, either you pass it on the gem install:

gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.3/bin/pg_config

Or you set the PATH properly. Since that might be too much, to temporarily set the PATH:

export PATH=%PATH:/Applications/Postgres.app/Contents/Versions/9.3/bin/

edited May 23 '17 at 12:34

Community

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answered Sep 26 '14 at 22:39

cregox

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for specific version: `gem install pg -v '0.17.1' -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.3/bin/pg_config` – Dan Sandland Mar 24 '15 at 19:06
There is a symlink folder called `latest` inside of the Postgres.app contents folder that is useful in case 9.3 is no longer shipped. ```gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/latest/bin/pg_config``` – Stephen Silber Jun 25 '18 at 16:27

score 29 · Answer 5 · edited May 22 '20 at 06:23

29

This worked in my case:

sudo apt-get install libpq-dev

I used:

Ubuntu 14.04.2 LTS
Ruby 2.2.2
Rails 4.2.1

edited May 22 '20 at 06:23

the Tin Man

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answered Jun 16 '15 at 13:53

Zainal

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Lasse Skindstad Ebert · Answer 6 · 2014-04-18T11:13:33.133

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I hadn't postgresql installed, so I just installed it using

sudo apt-get install postgresql postgresql-server-dev-9.1

on Ubuntu 12.04.

This solved it.

Update:

Use the latest version:

sudo apt-get install postgresql-9.3 postgresql-server-dev-9.3

edited Apr 18 '14 at 11:13

answered Sep 08 '12 at 19:49

Lasse Skindstad Ebert

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Fixed the problem for me but on a mac (with homebrew) I had to run this command: `brew install postgresql` – gMale Jul 19 '14 at 19:45

score 14 · Answer 7 · answered Aug 04 '15 at 10:11

14

If you are using Postgres.app on Mac, you may resolve this issue once and for all like this:

First gem uninstall pg, then edit your ~/.bash_profile or ~/.zshrc file or equivalent and add:

# PostgreSQL bin path
export PATH=$PATH:/Applications/Postgres.app/Contents/Versions/9.4/bin

Then bundle install and gem install pg should both work as expected.

answered Aug 04 '15 at 10:11

Darme

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Thanks, it also works using brew installed postgreSQL # PostgreSQL bin path export PATH=$PATH:/usr/local/Cellar/postgresql/9.5.0/bin/ – Benoit Jan 21 '16 at 07:56
Thanks! I switched from brew installed postgres to Postgress.app and had this problem – luigi7up Feb 13 '21 at 16:35

score 14 · Accepted Answer · edited May 23 '17 at 12:34

14

Answered here: Can't install pg gem on Windows

There is no Windows native version of latest release of pg (0.10.0) released yesterday, but if you install 0.9.0 it should install binaries without issues.

edited May 23 '17 at 12:34

Community

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answered Jan 28 '11 at 10:34

Nikita Barsukov

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score 11 · Answer 9 · edited Jul 27 '20 at 01:31

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On macOS (El Capitan). You can simply use: brew install postgresql

edited Jul 27 '20 at 01:31

Aaron Brager

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answered Jan 07 '16 at 16:50

Jones Agyemang

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Yes! This was all I needed! Install on clean OS X, no Postgres.app – Lane Rettig Jun 08 '17 at 03:02

jstnno · Answer 10 · 2013-02-07T21:33:16.440

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$ PATH=$PATH:/Library/PostgreSQL/9.1/bin sudo gem install pg

replace the 9.1 for the version installed on your system.

edited Feb 07 '13 at 21:33

answered Feb 29 '12 at 05:52

jstnno

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This helped me on a mac, anyone know what the default path is and how to change it? – Steve Jul 01 '12 at 09:05
Works on OS X Maveric – Marek Kirejczyk Mar 22 '14 at 17:13

Corey · Answer 11 · 2021-01-28T15:19:07.620

Ubuntu 20.10 (pop!_os)
Ruby 2.7.2
Rails 3.1.0
Postgresql 12

Uninstall and then reinstall postgresql-client libpq5 libpq-dev

sudo apt remove postgresql-client libpq5 libpq-dev
sudo apt install postgresql-client libpq5 libpq-dev

Then install the pg gem again pointing at /usr/lib to find the pg library:

gem install pg  --   --with-pg-lib=/usr/lib

Output (what you should see after the previous command):

Building native extensions with: '--with-pg-lib=/usr/lib'
This could take a while...
Successfully installed pg-1.2.3
Parsing documentation for pg-1.2.3
Installing ri documentation for pg-1.2.3
Done installing documentation for pg after 1 seconds
1 gem installed

Gem should install, then continue with normal bundle install or update:

bundle
bundle install
bundle update

score 3 · Answer 12 · answered Mar 10 '15 at 05:40

3

For Mac Users

PATH=$PATH:/Library/PostgreSQL/9.4/bin/ gem install pg

This should do the trick

answered Mar 10 '15 at 05:40

Ronak Jain

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score 3 · Answer 13 · edited Oct 22 '16 at 10:02

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Use with ARCH flag.

sudo env ARCHFLAGS="-arch x86_64" gem install pg

This resolved the same issue you are having.

edited Oct 22 '16 at 10:02

yeyeyerman

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answered Jan 11 '16 at 17:42

Aman Chhabra

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score 3 · Answer 14 · answered Jan 28 '11 at 18:14

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The pg gem requires the postgresql client libraries to bind against. This error usually means it can't find your Postgres libraries. Either you don't have them installed or you may need to pass the --with-pg-dir= to your gem install.

answered Jan 28 '11 at 18:14

Winfield

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score 2 · Answer 15 · answered May 02 '13 at 08:48

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I'd this issue on Linux Mint (Maya) 13, And I fixed it by Installing postgresql and postgresql-server :

apt-get install postgresql-9.1 

sudo apt-get install postgresql-server-dev-9.1

answered May 02 '13 at 08:48

SAIDI Belkacem

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score 2 · Answer 16 · answered Jan 15 '18 at 20:46

Regardless of what OS you are running, look at the logs file of the "Makefile" to see what is going on, instead of blindly installing stuff.

In my case, MAC OS, the log file is here:

/Users/za/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/extensions/x86_64-darwin-15/2.3.0-static/pg-1.0.0/mkmf.log

The logs indicated that the make file could not be created because of the following:

Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers

Inside the mkmf.log, you will see that it could not find required libraries, to finish the build.

checking for pg_config... no
Can't find the 'libpq-fe.h header
blah blah

After running "brew install postgresql", I can see all required libraries being there:

za:myapp za$ cat /Users/za/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/extensions/x86_64-darwin-15/2.3.0-static/pg-1.0.0/mkmf.log | grep yes
find_executable: checking for pg_config... -------------------- yes
find_header: checking for libpq-fe.h... -------------------- yes
find_header: checking for libpq/libpq-fs.h... -------------------- yes
find_header: checking for pg_config_manual.h... -------------------- yes
have_library: checking for PQconnectdb() in -lpq... -------------------- yes
have_func: checking for PQsetSingleRowMode()... -------------------- yes
have_func: checking for PQconninfo()... -------------------- yes
have_func: checking for PQsslAttribute()... -------------------- yes
have_func: checking for PQencryptPasswordConn()... -------------------- yes
have_const: checking for PG_DIAG_TABLE_NAME in libpq-fe.h... -------------------- yes
have_header: checking for unistd.h... -------------------- yes
have_header: checking for inttypes.h... -------------------- yes
checking for C99 variable length arrays... -------------------- yes

score 2 · Answer 17 · answered Mar 21 '18 at 14:34

I've been experiencing this annoying problem with PG for years. I created this gist to help.

The following command always work for me.

# Substitute Postgres.app/Contents/Versions/9.5 with appropriate version number
sudo ARCHFLAGS="-arch x86_64" gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.5/bin/pg_config

gist: https://gist.github.com/sharnie/5588340cf023fb177c8d

score 1 · Answer 18 · answered Oct 18 '12 at 07:17

I had to do this on CentOS 5.8. Running bundle install kept causing issues since I couldn't force it to use a particular PG version.

I can't yum erase postgresql postgresql-devel either, because of dependency issues (it would remove php, http etc)

The solution? Mess $PATH temporarily to give preference to the update pgsql instead of the default one:

export PATH=/usr/pgsql-9.2/bin:$PATH
bundle install

Basically, with the above commands, it will look at /usr/pgsql-9.2/bin/pg_config before the one in /usr/bin/pg_config

score 1 · Answer 19 · edited Jun 16 '15 at 19:49

1

If you are using jruby instead of ruby you will have similar issues when installing the pg gem. Instead you need to install the adaptor:

gem 'activerecord-jdbcpostgresql-adapter'

edited Jun 16 '15 at 19:49

Qiu

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answered Jun 16 '15 at 19:26

Nuri

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score 1 · Answer 20 · answered Jun 07 '16 at 20:59

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On Mac brew install postgres THEN bundle install

answered Jun 07 '16 at 20:59

Yar HTUT

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score 1 · Answer 21 · answered May 03 '21 at 03:21

I'm on Linux (Pop_OS) 20.10 and using a version manager (asdf) for Ruby (and others) and after trying a million different ways to sort it including all of the above

TLDR

gem install pg -v '1.2.3' -- --with-pg-config='/home/username/.asdf/installs/postgres/12.6/bin/pg_config'

Find the PG install for the right version and point to the pg_config in the bin directory

score 0 · Answer 22 · answered Jan 04 '13 at 06:29

0

You just go to here to see if your pg version support Win32 platform, then use this command to install:

gem install pg -v 0.14.1 --platform=x86-mingw32

answered Jan 04 '13 at 06:29

revskill

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score 0 · Answer 23 · answered Mar 17 '22 at 23:13

0

If you are using asdf to install postgres, just install pg gem like this:

asdf global postgres <version>
gem install pg

answered Mar 17 '22 at 23:13

Siwei

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score 0 · Answer 24 · answered Jun 16 '23 at 16:06

0

Note that this library is called libpq-devel on some other Linux distrubitions, like Fedora, RHEL, etc. So it'd be sudo dnf install libpq-devel on Fedora.

https://unix.stackexchange.com/questions/594466/how-to-install-libpq-dev-on-fedora

answered Jun 16 '23 at 16:06

Niko Dunk

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score 0 · Answer 25 · answered Jun 19 '23 at 04:52

If you are using MacOS, check the mkmf.log to see whether it requires an xcode licence

Run:

sudo xcodebuild -license

and type agree in the prompt.

Plus if you have installed postgres.

where pg_config

Then

gem install pg:1.4.5 -- --with-pg-config='/usr/local/opt/libpq/bin/pg_config'

Hope it helps

unable to install pg gem

25 Answers25

On a Mac

Linked