Trouble with incorporating Xpress solver in Julia

Question

I'm trying to use Xpress solver in Julia-Jump. However, I have trouble to make Julia find the location of my Xpress installation. I'm using a Mac. I downloaded the Xpress, obtained license, put the license in the right folder, added these following lines in bash_profile:

# >>> XPRESS setup
Export /XPRESSDIR="Applications/FICO Xpress/Xpress Workbench.app/Contents/Resources/xpressmp/lib/"
export XPRESS=$XPRESSDIR/bin
source /Applications/FICO\ Xpress/xpressmp/bin/xpvars.sh
source /Applications/FICO\ Xpress/Xpress\ Workbench.app/Contents/Resources/xpressmp/bin/xpvars.sh

Then in Julia, I set:

ENV["EXPRESSDIR"] = "/Applications/FICO Xpress/xpressmp/Applications/FICO Xpress/xpressmp/"

using Pkg
Pkg.add("Xpress")

And have no issue. However when I tried

Pkg.build("Xpress")

I have an error of:

Building Xpress → `~/.julia/scratchspaces/44cfe95a-1eb2-52ea-b672-e2afdf69b78f/502f7c1142f5233137fa02e27b22d150b78a6db3/build.log`
ERROR: Error building `Xpress`: 
ERROR: LoadError: Unable to locate Xpress installation.
Please check your enviroment variable XPRESSDIR.

Even though when I checked:

optimizer --help

I got:

FICO Xpress Solver 64bit v8.12.3 Jul 21 2021
(c) Copyright Fair Isaac Corporation 1983-2020. All rights reserved
 Optimizer v38.01.04    [/Applications/FICO Xpress/Xpress Workbench.app/Contents/Resources/xpressmp/lib/libxprs.dylib]

Which means my Xpress solver is installed successfully and is in the right path. So how come Julia still cannot find it?

Answer 1

In Julia, you have called it EXPRESSDIR, not XPRESSDIR.

Try

ENV["XPRESSDIR"] = "/Applications/FICO Xpress/Xpress Workbench.app/Contents/Resources/xpressmp"