Installing Prophet on CentOS

I’ve been struggling to get the {prophet} package to install on two RHEL 7 systems. Since I only have intermittent access to those systems I opted to use a local install of CentOS as a proxy environment. These instructions work for CentOS and should generalise to RHEL too.

Setting Up the Environment

The first thing that I needed to do was create an environment for testing.

Download the DVD ISO or Everything ISO from either of these sources:

• latest version of CentOS 7 (build: 1908) or
• older version of CentOS 7 (build: 1804).

Install the ISO on VirtualBox. Launch the image and login.

Install R

First install R.

$ sudo yum update
$ sudo yum install epel-release
$ sudo yum install R

Installing R Packages

Now you can launch R and start installing packages.

> install.packages("tidyverse")

If you run into issues with certificates (I did!) you can do the following:

> options(repos = c(CRAN = "http://cran.rstudio.com/"))

Updating Compiler

You’ll find that most R packages will install smoothly simply using install.packages(). Not so with the prophet package though. The problem is that this package requires a compiler which supports the C++14 standard. The default compiler which comes bundled with Centos 7, gcc 4.8.5, does not support the C++14 standard.

So the first thing that you need to do is get a new compiler by installing another SCL (Software Collection).

$ sudo yum install centos-release-scl
$ sudo yum install devtoolset-8

Now activate the SCL and check the compiler version.

$ scl enable devtoolset-8 bash
$ gcc --version

You should now have gcc 8.3.1.

You’ll probably want to use this compiler by default now. You can automatically enable the SCL at login by adding the following line to your ~/.bash_profile:

. /opt/rh/devtoolset-8/enable

Installing Prophet

Check on the location of g++.

$ which g++
/opt/rh/devtoolset-8/root/usr/bin/g++

Create a ~/.R/Makevars file with the following content:

CXX14=/opt/rh/devtoolset-8/root/usr/bin/g++
CXX14FLAGS=-O3 -march=native -mtune=native -fPIC

Update the value of CXX14 if the location of the compiler differs on your system.

Now start R. We’ll install {rstan} first.

> install.packages("rstan")

Once the install is finished you can do a quick test (thanks Ben Letham!) to verify that it works.

library(rstan)
fit <- stan(model_code = 'parameters {real y;} model {y ~ normal(0,1);}')
mean(extract(fit)$y)
#
# Result should be close to 0.

Once {rstan} is working, we’ll move onto {prophet}.

> install.packages("prophet")

You might get an error like this (probably on RHEL but not on CentOS):

Error in dyn.load(libLFile) :
  unable to load shared object '/tmp/RtmpKZb6vU/file158135f4cea.so':
  /tmp/RtmpKZb6vU/file158135f4cea.so: failed to map segment from shared object: Operation not permitted

This indicates a permission problem on /tmp. I investigated and found:

df -h
Filesystem                          Size  Used Avail Use% Mounted on
/dev/mapper/vg_00-lv_root            15G  4.0G   11G  28% /
devtmpfs                             32G     0   32G   0% /dev
tmpfs                                32G     0   32G   0% /dev/shm
tmpfs                                32G  3.2G   29G  11% /run
tmpfs                                32G     0   32G   0% /sys/fs/cgroup
/dev/sda1                           497M  209M  289M  42% /boot
/dev/mapper/vg_00-lv_home           2.4G  1.2G  1.3G  49% /home
/dev/mapper/vg_00-lv_var            8.3G  979M  7.3G  12% /var
/dev/mapper/vg_00-lv_tmp            473M   25M  449M   6% /tmp
/dev/mapper/vg_00-lv_var_tmp        473M   25M  449M   6% /var/tmp
/dev/mapper/vg_00-lv_var_log        4.7G  1.1G  3.6G  23% /var/log
/dev/mapper/vg_00-lv_var_log_audit  473M   55M  419M  12% /var/log/audit
tmpfs                               6.3G     0  6.3G   0% /run/user/0

Remounting /tmp did the trick.

$ sudo mount /tmp -o remount,exec

This should get {prophet} installed. I’d be super interested to know if there’s an alternative (simpler!) approach to getting this working or if anybody encounters other installation issues.