Is cross-cell configuration possible?

I did some experiments on cells (https://github.com/njlr/buck-cell-config) and found that each cell compiles with its own .buckconfig, rather than the .buckconfig at the top-level. This is reasonable, but now what I expected!

This can cause issues when trying to set project-global settings such as compiler flags and language standards. I would rather not edit the .buckconfig in each target because it means modifying each cell.

Does Buck provide a mechanism for injecting global settings to all cells in a project?

I’m envisioning something like this, in order of stacking:

.buckconfig.global
.buckconfig
.buckconfig.local

[njlr]

Thanks @bertmaher.

This capability is quite critical for us, and we would be willing to contribute the code if required to make it happen. Do you think one of the Buck team could provide some design direction?

cc @nikhedonia

[cpsauer]

I wanted to say that I’d had the same expectations as @njlr. It’s problematic to not be able to set, e.g., language standards, deployment targets (see referenced issue above), optimization levels, and debug symbols project-wide. Perhaps a better behavior would just be to have cells inherit their parent’s configuration by default?

In the meantime, for anyone else reading, you can solve this with a bit of a hack. Just prefix each cell’s .buckconfig with an import of the parent cell’s .buckconfig, i.e., <file:../../../../.buckconfig>. This should really be inheritance, because buck’s INI parser takes the second value if you specify something twice (at least in my tests on macOS 10.14).