Autoconf 'subdir-objects' warning

[Daniel Aleksandersen]

src/blocker/Makefile.am:5: warning: source file '../common/simclist.c' is in a subdirectory,
src/blocker/Makefile.am:5: but option 'subdir-objects' is disabled
automake: warning: possible forward-incompatibility.
automake: At least a source file is in a subdirectory, but the 'subdir-objects'
automake: automake option hasn't been enabled.  For now, the corresponding output
automake: object file(s) will be placed in the top-level directory.  However,
automake: this behaviour will change in future Automake versions: they will
automake: unconditionally cause object files to be placed in the same subdirectory
automake: of the corresponding sources.
automake: You are advised to start using 'subdir-objects' option throughout your
automake: project, to avoid future incompatibilities.
src/fw/Makefile.am:24: warning: source file '../common/simclist.c' is in a subdirectory,
src/fw/Makefile.am:24: but option 'subdir-objects' is disabled

automake 1.15

[Kevin Zheng]

As far as I can tell this is not a bug. We don't currently rely on object files being built in the top-level. Setting subdir-objects seems to cause issues running make distclean last time I checked.

[Daniel Aleksandersen]

It’s warning that a behavioral change in a future version of Make will introduce a bug as sshguard is relying on behavior that is about to change. (If I’m reading it correctly.)

[Kevin Zheng]

The "possible forward-incompatibility" seems to suggest that if SSHGuard relies on the objects to be in a certain place, future versions will break. If SSHGuard doesn't rely on this, we should be free to ignore it.

That said, this warning is pretty annoying, and I'm not sure what the full ramifications of it are.

[Kevin Zheng]

Removing version: 2.0 (automated comment)