The documentation for installing OMP from Github seems to be lacking in my opinion.
Github page (GitHub - pkp/omp: Open Monograph Press) mentions some stuff but lacks specific instructions on setting up config.inc.php, and setting up cache and public directories, and directories for submission files.
The link “See Wiki for more complete development guide.” doesn’t work.
README under docs directory (omp/docs at main · pkp/omp · GitHub) doesn’t mention installing from Github but rather seems to be for installing from downloaded pre-made packages.
The PKP Admin guide (Managing the Server Environment) refers to Github, which again takes us to the initial problem of lacking detailed information and broken links.
Edit: Also, it seems important to note that for successful installation, one should install php extensions:
and restart the apache2 service. Otherwise, the install page will appear blank and list errors in the error log.