Configuration failed because libpq was not found.

[baderstine]

Apologies @jeroen and @krlmlr for bringing this up as it seems to have been addressed previously: #118 and #350

---

I am running RHEL 8.9 using R 4.3.3 and attempted to install RPostgres, which failed with the following error:

trying URL 'https://cloud.r-project.org/src/contrib/RPostgres_1.4.7.tar.gz'
Content type 'application/x-gzip' length 1476313 bytes (1.4 MB)
==================================================
downloaded 1.4 MB

* installing *source* package ‘RPostgres’ ...
** package ‘RPostgres’ successfully unpacked and MD5 sums checked
** using staged installation
Using PKG_CFLAGS=
Using PKG_LIBS=-lpq
Using PKG_PLOGR=
------------------------- ANTICONF ERROR ---------------------------
Configuration failed because libpq was not found. Try installing:
 * deb: libpq-dev libssl-dev (Debian, Ubuntu, etc)
 * rpm: postgresql-devel (Fedora, EPEL)
 * rpm: postgreql8-devel, postgresql92-devel, postgresql93-devel, or postgresql94-devel (Amazon Linux)
 * csw: postgresql_dev (Solaris)
 * brew: libpq (OSX)
If libpq is already installed, check that either:
(i)  'pkg-config' is in your PATH AND PKG_CONFIG_PATH contains
     a libpq.pc file; or
(ii) 'pg_config' is in your PATH.
If neither can detect , you can set INCLUDE_DIR
and LIB_DIR manually via:
R CMD INSTALL --configure-vars='INCLUDE_DIR=... LIB_DIR=...'
--------------------------[ ERROR MESSAGE ]----------------------------
<stdin>:1:10: fatal error: libpq-fe.h: No such file or directory
compilation terminated.
-----------------------------------------------------------------------
ERROR: configuration failed for package ‘RPostgres’
* removing ‘/opt/R/4.3.3/lib/R/library/RPostgres’

The downloaded source packages are in
	‘/tmp/RtmpFVocGF/downloaded_packages’
Updating HTML index of packages in '.Library'
Making 'packages.html' ... done
Warning message:
In install.packages("RPostgres") :
  installation of package ‘RPostgres’ had non-zero exit status

I attempted the following:

1. sudo yum install postgresql-devel
2. sudo yum install libpq
   which did install these things, but did not resolve the install error.

I tried export PATH=$PATH:/usr/pgsql-15/bin/pg_config as well (thinking this would address (ii) above, by adding pg_config to my PATH) but this also did not resolve the error. I can confirm that neither condition in (i) is true, nor do I know how to address them.

Other output requested in the referenced issues:

$ pkg-config --cflags libpq
Package libpq was not found in the pkg-config search path.
Perhaps you should add the directory containing `libpq.pc'
to the PKG_CONFIG_PATH environment variable
Package 'libpq', required by 'virtual:world', not found

... and the closest I can find to libpq.pc appears to be /usr/lib64/libpq.so

[krlmlr]

Thanks. Do you need

export PATH=$PATH:/usr/pgsql-15/bin

? I do wonder why it's not put on the PATH automatically.

[jeroen]

FWIW I was able to install in rocky-8 using only dnf install libpq-devel without customizing any paths.

[baderstine]

Aha! This seems to have worked:
export PATH=$PATH:/usr/pgsql-15/bin

(I also tried: export PKG_CONFIG_PATH=/usr/lib64 but this didn't work. I can confirm that the export PATH ... fix above was thing that actually got it to work.)

[krlmlr]

Thanks, Jeroen. Should we then add:

* rpm: libpq-devel (RedHat, Rocky)

or similar to the configure output?

[baderstine]

When I try that, it doesn't seem to change anything:

$ sudo dnf install libpq-devel
Updating Subscription Management repositories.
github_git-lfs                                                                                               691  B/s | 833  B     00:01    
github_git-lfs-source                                                                                        673  B/s | 833  B     00:01    
Red Hat Enterprise Linux 8 for x86_64 - AppStream (RPMs)                                                     193 kB/s | 4.5 kB     00:00    
Red Hat Enterprise Linux 8 for x86_64 - BaseOS (RPMs)                                                        170 kB/s | 4.1 kB     00:00    
rhel8 epel                                                                                                   147 kB/s | 2.3 kB     00:00    
Package postgresql12-devel-12.19-1PGDG.rhel8.x86_64 is already installed.
Package postgresql13-devel-13.15-1PGDG.rhel8.x86_64 is already installed.
Package postgresql14-devel-14.12-1PGDG.rhel8.x86_64 is already installed.
Package postgresql15-devel-15.7-1PGDG.rhel8.x86_64 is already installed.
Package postgresql16-devel-16.3-3PGDG.rhel8.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!

[baderstine]

I modified my .bashrc file to include export PATH=$PATH:/usr/pgsql-15/bin so that this would persist across sessions, although other users on the machine would need to modify their own .bashrc file. However, I would have thought that this would be added to the path by the dnf/yum install? Am I missing something?

[krlmlr]

Should this be raised with the maintainers of the relevant RHEL packages? It seems that we have a workaround here.