Could not find module `discourse-common/lib/icon-library`

Hi,

I am trying to follow
https://meta.discourse.org/t/use-old-commit-to-build-discourse/108028/2

But I am getting error any idea?

I, [2019-01-31T17:08:39.945102 #15]  INFO -- : > cd /var/www/discourse/plugins && mkdir -p plugins
I, [2019-01-31T17:08:39.950402 #15]  INFO -- :
I, [2019-01-31T17:08:39.950737 #15]  INFO -- : > cd /var/www/discourse/plugins && git clone https://github.com/discourse/docker_manager.git
Cloning into 'docker_manager'...
I, [2019-01-31T17:08:41.890949 #15]  INFO -- :
I, [2019-01-31T17:08:41.891630 #15]  INFO -- : > cd /var/www/discourse/plugins && git clone https://github.com/discourse/discourse-solved.git
Cloning into 'discourse-solved'...
I, [2019-01-31T17:08:43.344731 #15]  INFO -- :
I, [2019-01-31T17:08:43.345246 #15]  INFO -- : > cd /var/www/discourse/plugins && cd discourse-solved
I, [2019-01-31T17:08:43.349650 #15]  INFO -- :
I, [2019-01-31T17:08:43.350051 #15]  INFO -- : > cd /var/www/discourse/plugins && get reset --hard 7745adb6eb0c1d1b2a37c9441c3877b7eec087cd
sh: 1: get: not found
I, [2019-01-31T17:08:43.354172 #15]  INFO -- :
I, [2019-01-31T17:08:43.354702 #15]  INFO -- : Terminating async processes
I, [2019-01-31T17:08:43.354881 #15]  INFO -- : Sending INT to HOME=/var/lib/postgresql USER=postgres exec chpst -u postgres:postgres:ssl-cert -U postgres:postgres:ssl-cert /usr/lib/postgresql/10/bin/postmaster -D /etc/postgresql/10/main pid: 70
I, [2019-01-31T17:08:43.355271 #15]  INFO -- : Sending TERM to exec chpst -u redis -U redis /usr/bin/redis-server /etc/redis/redis.conf pid: 186
2019-01-31 17:08:43.355 UTC [70] LOG:  received fast shutdown request
186:signal-handler (1548954523) Received SIGTERM scheduling shutdown...