On Tue, Oct 15, 2024, at 10:38 AM, suzuki toshiya wrote: > I'm looking for a combination of the target to include sub-packages > which is built conditionally. > > A package "X" include a libary "Y" as a subpackage, like ... > Y is often installed as an external or system library, so X/configure > calls AC_CONFIG_SUBDIRS([Y]) in some cases, not always.
You need to call AC_CONFIG_SUBDIRS([Y]) unconditionally. Many things break if you call it conditionally, not just what you have already tripped over. Not only this, but Y's configure script needs to actually run and its Makefiles need to be generated unconditionally. (The basic _issue_ is what you've already tripped over: Automake needs to know _statically_ all of the files included in package X. But many other things besides "make dist" depend on this.) Instead, I suggest that you have Y detect when it is being configured as an embedded subpackage that will not actually be used. For example, if X decides to build Y based on the value of a --with-system-Y configure switch, Y's configure.ac can itself respond to --with-system-Y by skipping all its system probes and using Automake conditionals to avoid building the library. As I recall, AC_CONFIG_SUBDIRS([Y]) will pass --with-system-Y down to Y's configure.ac, so you don't need to do anything special there. zw
