test_sign: Assertion `hydro_sign_verify(sig, msg, sizeof msg, ctx, kp.pk) == 0' failed.

As discussed on twitter:

With jedisct1/libhydrogen/master:

$ git diff
diff --git a/Makefile b/Makefile
index 12f9e80..85eb1fc 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-WFLAGS ?= -Wall -Wextra -Wmissing-prototypes -Wdiv-by-zero -Wbad-function-cast -Wcast-align -Wcast-qual -Wfloat-equal -Wmissing-declarations -Wnested-externs -Wno-unknown-pragmas -Wpointer-arith -Wredundant-decls -Wstrict-prototypes -Wswitch-enum -Wno-type-limits
+WFLAGS ?= -Wall -Wextra -Wmissing-prototypes -Wdiv-by-zero -Wbad-function-cast -Wcast-align -Wcast-qual -Wfloat-equal -Wmissing-declarations -Wnested-externs -Wno-unknown-pragmas -Wpointer-arith -Wredundant-decls -Wstrict-prototypes -Wswitch-enum -Wno-type-limits -ggdb
 CFLAGS ?= -Os -fno-exceptions $(WFLAGS)
 CFLAGS += -I.
 OBJ = hydrogen.o

$ make test
rm -f tests/tests.done
tests/tests && touch tests/tests.done
tests: tests/tests.c:236: test_sign: Assertion `hydro_sign_verify(sig, msg, sizeof msg, ctx, kp.pk) == 0' failed.
Aborted
Makefile:29: recipe for target 'test' failed
make: *** [test] Error 134

ENV: debian testing, Linux x86_64, gcc 6.3.0 / clang-5.0 (recent decent git)

CPU Flags (8x Intel(R) Xeon(R) CPU E5-2680 v4 @ 2.40GHz):

fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm rdseed adx smap xsaveopt arat
bugs

jedisct1 / libhydrogen

test_sign: Assertion `hydro_sign_verify(sig, msg, sizeof msg, ctx, kp.pk) == 0' failed. #2