My steps to reproduce on Debian 10: enable php like here: https://tecadmin.net/install-apache-php-fpm-debian-10/ Install like here (I did not use the firewall ufw, too much fuzz on a local, temporary desktop machine): https://www.howtoforge.com/how-to-install-and-configure-mantis-bug-tracker-on-ubuntu/ - Used 2.24.2 instead, and as tar, not zip - dont use admin but root account for initial db creation (shouldnt make a difference, though) edit /etc/gitlab/gitlab.rb and change external URL to external_url 'http://192.168.1.13:10443' - create a project in mantisbt (mine is "Test") Install gitlab: https://about.gitlab.com/install/#debian Use Community Edition of gitlab, and I had to work around my companies https tinkerer like that (easy but evil way. I dont know why curl doesnt honor the certificates I've installed in /etc/ssl/certs/ca-certificates.crt): curl --insecure https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/script.deb.sh | sed 's/curl -/curl --insecure -/g' | sudo bash EXTERNAL_URL="http://192.168.1.13:10443" apt-get install gitlab-ce Create a new project "test" Click on your Profile icon in the upper right corner to create an API Token: - Settings (User Settings) => Access Tokens - Name: gitlab - Scopes: tick all checkboxes - Copy the access token data (mine was SBFDuUQY9YXXXXXXXbLE) Install Source Integration Plugin from https://github.com/mantisbt-plugins/source-integration (https://github.com/mantisbt-plugins/source-integration.git master branch for mantisbt 2.x) cp -r Source /var/www/html/mantis/plugins/ cp -r SourceGitlab /var/www/html/mantis/plugins/ chown -R www-data:www-data /var/www/html/mantis/plugins/Source* Install Source Integration Plugin and its Gitlab child (Just my experience: a thing I stumbled accross was that Source Integration Plugin was not in the list, instead there was the "VCS Basisintegration 2.4.0" which, on my first attempts I totally misunderstood.) Configure Source Plugin - tick all checkboxes under Enabled Features - change Isses references RegEx (Pass 2) to /(?:fixe?d?s?|resolved?s?)+\s*(?:bug?s?)*+\s*:?\s+(?:#(?:\d+)[,\.\s]*)+/i - generate API Key with openssl rand -hex 12 and copy that into field "API Key" and write it down for later - click Update Configure Project Archive - Name: test - GitLab Root: http://192.168.1.13:10443 - Gitlab Repository Name root/test - Gitlab API Key from Gitlab: copy your acces token from above step here (mine was SBFDuUQY9YXXXXXXXbLE) - click Update button Configure Webhook in gitlab: - Go to Admin area => Settings => Network - click on "Outbound requests" - tick "Allow requests to the local network from web hooks and services" - click "Save changes" - Go into your repository - there on Settings => Webhooks - insert http://mantis.eu.local/plugin.php?page=Source/checkin&api_key=YOURAPIKEYTHATYOUWROTEDOWN - insert that one into "Secret Token Field" again - just in case Source Integration Plugin will switch on getting the secret token from Headers (that are encoded in ssl, unlike the URL which blows out the "secret" token into the www ;-)) - Tick every checkbox even though that is nonsense - Untick "Enable SSL verification" - click "Add webhook" - check that it works: scroll down and click in the webhook's "Test" button and select "Push event" which hopefully yields a 200 Create a user that represents your git user in mantisbt Create a "patch" in gitlab to get a note in mantis to our created bug #1: - checkout your project git clone http://192.168.1.13:10443/root/test.git - Create a new file. Name it test.txt - Type in some text - git commit test.txt Commit message is something like bug #1: test - git push - check that mantisbt has a note added to the issue - edit your file again, commit with "fixed bug #1: test" git commit test.txt - git push ====> bug fixed - Go to Manage => Manage Projects => Test - Versions => 1.0.0 - Add Version - Create Bug report - change file and commit it with fixed bug #2: test - git push ====> bug fixed Install postgresql and php postgresql connector - apt install postgresql-11 php7.3-pgsql - install mantis to postgresql as above, just select postgresql Do exactly as above. Result is bug fixed until you add a target version, the bug #2 is not getting fixed! Add my patch => bug fixed. So in summary: with postgresql there seems to be a problem with the db_param getting reset somewhere in the middle of the queries, so my patch is not the right one. Postgresql database acces in mantis shoudl be fixed instead.