Missing CMake target_include_directory for Kyber768

[jschanck]

Upstream Kyber768_META.yml is missing a "common_dep: common_ref" line, which results in OQS_ENABLE_KEM_kyber_768 being omitted from this if statement:

liboqs/src/kem/kyber/CMakeLists.txt

Lines 8 to 12 in 1256e3b

	if(OQS_ENABLE_KEM_kyber_512 OR OQS_ENABLE_KEM_kyber_1024 OR OQS_ENABLE_KEM_kyber_512_90s OR OQS_ENABLE_KEM_kyber_768_90s OR OQS_ENABLE_KEM_kyber_1024_90s)
	add_library(kyber_common_ref OBJECT pqcrystals-kyber_common_ref/aes256ctr.c pqcrystals-kyber_common_ref/fips202.c)
	target_include_directories(kyber_common_ref PRIVATE ${CMAKE_CURRENT_LIST_DIR}/pqcrystals-kyber_common_ref)
	set(_KYBER_OBJS ${_KYBER_OBJS} $<TARGET_OBJECTS:kyber_common_ref>)
	endif()

If you try to build liboqs with only Kyber768 (and none of the other Kyber parameter sets), the build will fail with undefined references.

This can be reproduced using my feat.minimal-build branch (jschanck/liboqs@4feed617).

cmake -GNinja -DOQS_MINIMAL_BUILD=ON -DOQS_KEM_DEFAULT=OQS_KEM_alg_kyber_768  ..

[baentsch]

Bug confirmed. Probably something for @bhess?

Side note:

-DOQS_MINIMAL_BUILD=ON

This is a really nice new build switch: hope you intend to do a PR for this: Fast(er) build, (comparatively) small lib, (nearly) fully functioning. Nearly: tests/example_kem|sig fail due to "alg hardcoding" - logical as it's an example; but probably needs to be skipped in testing if this option is set.