How do I set up a Vala project with multiple namespaces in Meson?

Question

I realize this is a bit beyond the scope of elementary OS, per se, but all y'all seem to be the main users of Vala, and I'm not sure where else to ask this.

I am working on a project with a large number of classes (porting from another language, rather than starting from scratch), and the classes are organized into namespaces with corresponding subdirectories. I've declared all of the subdirectories and source files in Meson, but some (but not all!) using statements for these local namespaces give me errors like The namespace name '<top_level_namespace_ie_project_name>.Sql' could not be found.

Does this mean I am declaring my namespaces incorrectly? I based my structure off of an existing Vala project, and it's worth noting that some using declarations of local namespaces are working, but not others. I googled the error, but all of the results are from over a decade ago and/or deal with external libraries, rather than multiple namespaces within a single project.

And, if necessary, what sort of additional information would be useful for me to provide in order facilitate answering this question? I'm not quite to the point of listing my project repository publicly, but I can give individual access to anyone wanting to help answer this question, if it would help.

Thanks!

Answer 1

I googled another error message, meson configuration failed with exit code 256, and I found this Reddit thread suggesting I use the command meson builddir to get a more detailed summary of the Meson build error. It turned out that I had a typo in one of my meson.build files: in the middle of the file list one of the entries didn't end with ', like it was supposed to, so everything after that point was being ignored.

So basically if you think you've done everything correctly with Vala namespaces and Meson, and you're still getting using errors, meson builddir should help you find out what's wrong. (It would be nice if vala-vscode provided this information directly.)