Bug#919189: probabel FTBFS on arm64, likely due to Eigen 3 NEON code

[Adrian Bunk]

Source: probabel
Version: 0.5.0+dfsg-1
Severity: serious
Tags: ftbfs

https://buildd.debian.org/status/fetch.php?pkg=probabel&arch=arm64&ver=0.5.0%2Bdfsg-1&stamp=1538603399&raw=0

...
FAIL: test_bt
=============

Analysing BT...
BT check: dose vs. dose_fv                                             OK
BT check (add model): prob vs. prob_fv                                 OK
BT check (domin model): prob vs. prob_fv                               OK
BT check (over_domin model): prob vs. prob_fv                          OK
BT check (recess model): prob vs. prob_fv                              OK
2c2
< rs7247199 GAC A 0.5847 0.415 0.9299 0.8666 200 0.333517 19 204938 544.518 437.583 -567.387 435.04 1.75239
---
> rs7247199 GAC A 0.5847 0.415 0.9299 0.8666 200 0.333517 19 204938 544.518 437.583 -567.388 435.04 1.75239
BT check (2df model): prob vs. prob_fv                                 FAILED
FAIL test_bt.sh (exit status: 1)

============================================================================
Testsuite summary for ProbABEL 0.5.0
============================================================================
# TOTAL: 11
# PASS:  10
# SKIP:  0
# XFAIL: 0
# FAIL:  1
# XPASS: 0
# ERROR: 0
============================================================================
See checks/test-suite.log
Please report to genabel-devel at r-forge.wu-wien.ac.at
============================================================================
make[4]: *** [Makefile:713: test-suite.log] Error 1


I suspect this might be a problem with the NEON code in Eigen 3,
and the fact that this can be fixed with the following workaround
makes that even more probable:

--- debian/rules.old	2019-01-09 15:07:11.950823327 +0000
+++ debian/rules	2019-01-09 15:17:23.280539016 +0000
@@ -6,6 +6,10 @@
 
 export DEB_BUILD_MAINT_OPTIONS=hardening=+all
 
+ifeq ($(DEB_HOST_ARCH),arm64)
+  export DEB_CXXFLAGS_MAINT_APPEND = -march=armv8-a+nosimd
+endif
+
 include /usr/share/dpkg/default.mk
 
 # Location of the example files, will be converted to the