Settings schema 'com.github.Suzie97.epoch' is not installed - settings

Question

This is the gschema.xml code for my app:
<?xml version="1.0" encoding="UTF-8"?>
<schemalist>
<schema path="/com/github/Suzie97/epoch"
id="com.github.Suzie97.epoch"
gettext-domain - "com.github.Suzie97.epoch">
<key name="pos-x" type="i">
<default>360</default>
<summary>Most recent x position of Epoch</summary>
<description>Most recent x position of Epoch</description>
</key>
<key name="pos-y" type="i">
<default>360</default>
<summary>Most recent y position of Epoch</summary>
<description>Most recent y position of Epoch</description>
</key>
</schema>
</schemalist>
This is the meson.build file to install the gschema:
install_data(
'gschema.xml',
install_dir: join_paths (get_option ('datadir'), 'glib-2.0', 'schemas'),
rename: meson.project_name() + '.gschema.xml'
)
When I compile this error is displayed:
Settings schema 'com.github.Suzie97.epoch' is not installed
This is the post_install.py script:
#!/usr/bin/env python3
import os
import subprocess
install_prefix = os.environ['MESON_INSTALL_PREFIX']
schemadir = os.path.join(install_prefix, 'share/glib-2.0/schemas')
if not os.environ.get('DESTDIR'):
print('Compiling the gsettings schemas ... ')
subprocess.call(['glib-compile-schemas', schemadir])
Why is this happening?

Answer 1

There are various issues at play:
the name of the schema file should match your application's identifier—in this case, it would be com.github.Suzie97.epoch.gschema.xml
you should not rename the file on installation; just installing it under the glib-2.0/schemas data directory is enough
you should call glib-compile-schemas $datadir/glib-2.0/schemas to "compile" all the schemas once you installed your application; this is typically done as a post-installation script in Meson, using meson.add_install_script().
GSettings does not use the XML per se: the glib-compile-schemas tool will generate a cache file that will be shared by all applications using GSettings, and will be fast to load. This is why GSettings will warn you that the schema is not installed: you are missing that last compilation step.