I have deployed a fresh create-next-app project using the text-based lockfile (bun.lock) and the file was not automatically detected, hence npm was used for the build.
The issue can be solved via a custom installCommand, however it should not be needed, as automatic detection should be present as per the aforementioned PR
I have check the commits on github and couldn’t see anything related.
Despite this fact, the issue seems to have vanished and installing packages using bun with the text-based lockfile seems to work fine now.