Pre-lock custom hook per layer

[neilmehta24]

There are actions that we always need to take prior to locking a specific layer that we have. For example, when re-locking one of our application layers, we want to rebuild one of our wheels from source beforehand. It would be nice if we could specify that command in the layer toml like so.

[[applications]]
name="src"
...
pre-lock-hook="/path/to/python -m build relative/path/to/src"

[ncoghlan]

@neilmehta24 I assume the current workaround is just to run a wrapper script that knows about the pre-lock commands for the layers that have them, and executes them all before running the lock step?

(which would work for comprehensive stack builds, but completely ignore the layer selection logic for selective builds, hence the feature request)

[neilmehta24]

@neilmehta24 I assume the current workaround is just to run a wrapper script that knows about the pre-lock commands for the layers that have them, and executes them all before running the lock step?

(which would work for comprehensive stack builds, but completely ignore the layer selection logic for selective builds, hence the feature request)

Yes, the reason why it would be nice to have on a per-layer basis is so we can use --include filter to decide whether to run the hook or not.
Right now we are re-running all builds on every lock command. Which is fine for now since our builds are very fast. But when our build gets larger, ideally we don't have to re-implement the include filtering in our wrapper script.
Overall this issue is a low priority since we have workarounds.