/etc/fusionforge/config.ini.d/scmhg.ini is in fusionforge-plugin-scmhg 5.1.1-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | [scmhg]
default_server = "$core/web_host"
repos_path = "$core/chroot/scmrepos/hg"
plugin_status = valid
|