File paths not updated when using 'Package current QGIS project' option

[raherin]

When using the Mergin Maps plugin to upload an existing project using the 'Package current QGIS project' option, the paths to the newly created project's file paths are not updated in the new .qgz and .gpkg files. Instead, the project will still point to the original file paths resulting in unavailable layers when opening the project in the app for the first time or downloading it via the Mergin Maps Plugin on a separate machine. To reproduce this issue:

1. Download the attached .zip file containing a simple survey project
2. Extract the project from the .zip file
3. Open the project_create.qgz file in QGIS (in the example, I used 3.34 LTR)
4. Press the '+' button in on the Mergin Maps Plugin menu
5. In the project creation dialogue, select the 'Package current QGIS project' option to create the project
6. Click 'Next'
7. In the next dialogue window, select a different directory for the 'Create Mergin Maps Project in:' than the current project directory and press 'Finish'
8. Once the project creation is finished, download and open the project in the Mergin Maps mobile app and an error will appear stating that there are missing layers.

project_create.zip

There is a workaround if this error occurs after creating the project. After finishing step 7 in the above sequence, go to the new project directory and open the project in QGIS. Then follow the steps provided in the QGIS documentation to fix the paths to the layer data sources for each of the layers in your project and synchronise the changes in the plugin.

[drekseimertutje]

Any update on this issue?
We have about 100 employees which have this issue.
Some of them also have this issue when you synchronize an existing project.

[tomasMizera]

I just tried to reproduce the issue but could not. Maybe a silly question, but did you select the option "package" for gpkgs?

[drekseimertutje]

Hi Tomas,

Yes we do.

The strange thing is, my computer with the same QGIS and Plugin version does not have this issue.
Also, this issue only appeared for my colleagues after they got new laptops with fresh installs. Even with QGIS 3.24 and the previous version of the plugin does the issue arrise so to me, it means it is Windows (configuration) related.

Can you perhabs tell which environment variables (related to the layer file paths) are used by the plugin?

[raherin]

Another user has reported this problem while using QGIS 3.40.0 and Mergin Maps plugin version 2024.2.1

[ValentinBuira]

Hi,
I tried to reproduce it again, and unfortunately I could not reproduce the issue in the latest versions either.

Could you share the start path of the project and the destination path of the mergin project ?
in order to see:

• is there any specials characters ?
• is the path longer than 256 characters (it's a limitation of windows)

[raherin]

@ValentinBuira The path of the original on my machine is:
C:\Users\raahe\Documents\Projects\project_create

The path of the packaged project is:
C:\Users\raahe\Documents\Projects\package_test/1_package_test

Here is a screenshot of the packaged project pointing to the incorrect source path for the survey layer:

The project will still load if you open it on the same machine where the original is stored because the path still exists on that machine. However, if you open the project in the mobile app or download it on a different machine you get an error that the layer is unavailable.

[ValentinBuira]

Mmmm, I see nothing out of the ordinary about these paths, and in my tests it does point to the correct geopackage in the packaged project... This is quite infuriating