When no build dir is specified, cmake will warn:
Preprocessing libmultiprocess...
Configuring libmultiprocess...
CMake Warning:
No source or binary directory provided. Both will be assumed to be the
same as the current working directory, but note that this warning will
become a fatal error in future CMake releases.
It's unclear if this will actually ever become an error, but it's also easy enough to just supply the directory, and save this maybe breaking in future.
When no build dir is specified, cmake will warn:
```bash
Preprocessing libmultiprocess...
Configuring libmultiprocess...
CMake Warning:
No source or binary directory provided. Both will be assumed to be the
same as the current working directory, but note that this warning will
become a fatal error in future CMake releases.
```
It's unclear if this will actually ever become an error, but it's also easy
enough to just supply the directory, and save this maybe breaking in
future.
5 | @@ -6,7 +6,7 @@ $(package)_sha256_hash=$(native_$(package)_sha256_hash) 6 | $(package)_dependencies=native_$(package) capnp 7 | 8 | define $(package)_config_cmds 9 | - $($(package)_cmake) 10 | + $($(package)_cmake) .
In commit "build: specify cmake build dir for multiprocess depends build" (7c218dacd0e9602b8f755be42e96c49706f96305)
Note: I guess an alternate implementation could include the . in the _cmake variable, but this implementation seems good and more explicit. _cmake variable is defined here currently: https://github.com/bitcoin/bitcoin/blob/47bac475f044da0d8cd2e1f39fd2894f90dd0bd9/depends/funcs.mk#L172-L186
Code review ACK 7c218dacd0e9602b8f755be42e96c49706f96305. I guess the purpose of the warning is to encourage people not to build in the source directory, but reasons for encouraging this don't really apply to the depends build system, so it is appropriate to disable the warning.
ACK 7c218dacd0e9602b8f755be42e96c49706f96305, tested on Ubuntu 22.04.