Description of problem:
The new cryptsetup2 will use Argon2 as a KDF and because there is already libargon2 in rawhide, I tried to compile it against this system library (instead of our bundled code).

Unfortunately it seems that it uses libargon2 optimized (native) version that does not run on some systems - it crashes with illegal instruction.
You should probably compile it with reference implementation only (Debian does it as well).

Version-Release number of selected component (if applicable):
libargon2-20161029-1.fc28.x86_64

Steps to Reproduce:

Please download and run test code from
https://github.com/mbroz/libargon2_test (it only calculates two test vectors from RFC draft).

On my VM (VMware desktop) it crashes this way:

Program received signal SIGILL, Illegal instruction.
blake2b_compress (S=S@entry=0x7fffffffdfc0, block=block@entry=0x7fffffffe020 "\004") at src/blake2/blake2b.c:213
213             ROUND(r);
(gdb) bt
#0  blake2b_compress (S=S@entry=0x7fffffffdfc0, block=block@entry=0x7fffffffe020 "\004") at src/blake2/blake2b.c:213
#1  0x00007ffff7bd2fee in blake2b_final (S=S@entry=0x7fffffffdfc0, out=out@entry=0x7fffffffe0f0, outlen=outlen@entry=64) at src/blake2/blake2b.c:281
#2  0x00007ffff7bd2445 in initial_hash (blockhash=blockhash@entry=0x7fffffffe0f0 "", context=context@entry=0x7fffffffe1e0, type=Argon2_i) at src/core.c:566
#3  0x00007ffff7bd2211 in initial_hash (type=<optimized out>, context=0x7fffffffe1e0, blockhash=0x7fffffffe0f0 "") at src/core.c:580
#4  initialize (instance=instance@entry=0x7fffffffe180, context=context@entry=0x7fffffffe1e0) at src/core.c:588
#5  0x00007ffff7bd1032 in argon2_ctx (context=0x7fffffffe1e0, type=<optimized out>) at src/argon2.c:78
#6  0x0000000000400ae3 in argon2_test_vectors () at argon2_generic.c:181
#7  0x0000000000400baf in main (argc=1, argv=0x7fffffffe3c8) at argon2_generic.c:198

Expected results:
The libargon2 must be supportable on all hw configurations.
(If we later link cryptsetup to it, it will also appear in critical path...)