This is in reference to sys-kernel/gentoo-sources-2.4.25
In net/ipsec/alg/ipsec_alg_cryptoapi.c, there is a code chunk about line 64 like:
#error "get the cryptoapi"
however, grepping through the linux source tree, the only place where CRYPTO_API_VERSION_CODE exists is in that file.
Bug 45525 (systrace missing) seems similar to this one, as does 45450
(i2c missing) (which was closed because i2c was dropped on purpose...)
gentoo-sources-2.4.25 is no longer maintained. Could you please try with a newer version and reopen if the issue still exists there?