Tweak the platform quirks docs.

docs/reference/platforms/linux/system.rst

@@ -243,11 +243,10 @@ Platform quirks
 ===============
 
 Local path references and Docker builds
-~~~~~~~~~~~~~~~~~~~~~
-
-When referencing local paths in the ``requires`` and ``requirement_installer_args``
-configuration, be aware that those paths will not be available inside a Docker build
-context. `This is a known limitation that has workarounds available if needed
-<https://github.com/beeware/briefcase/issues/2081>`__, and support will eventually
-be added to Briefcase so that these paths work seamlessly like they do with other build
-targets.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Docker builds are not able to reference local paths in the ``requires`` and
+``requirement_installer_args`` configurations. This is because the Docker container only
+has access to specific file paths on the host system. See `issue #2018
+<https://github.com/beeware/briefcase/issues/2081>`__ for more discussion of the
+problem, and some possible workarounds.