Bug#946504: plplot: please force a lower optimization level on ppc64el

[Gianfranco Costamagna]

Source: plplot
Version: 5.15.0+dfsg-9
Severity: normal

Hello, looks like gcc compiler has some sort of bug (but the bug might be in the code), that makes the testsuite during build segfault if a -O3 is provided by the compiler.

This isn't a big deal for Debian users, because their gcc optimization level on ppc64el is -O2, but an user might have
a different level while rebulding it, so I think it might be worth forcing a lower value or fixing the bug.

"Patch" is following:

--- plplot-5.15.0+dfsg/debian/rules	2019-11-30 19:16:24.000000000 +0100
+++ plplot-5.15.0+dfsg/debian/rules	2019-12-10 00:02:22.000000000 +0100
@@ -8,7 +8,12 @@
 
 DEB_BUILD_MAINT_OPTIONS       := hardening=+all
 DPKG_EXPORT_BUILDFLAGS        := 1
+ifeq ($(DEB_HOST_ARCH), ppc64el)
+DEB_CFLAGS_MAINT_APPEND       := -fvisibility=hidden -O2
+else
 DEB_CFLAGS_MAINT_APPEND       := -fvisibility=hidden
+endif
+
 DEB_FFLAGS_MAINT_APPEND       := -fvisibility=hidden
 # Don't add -fvisibility=hidden to CXXFLAGS for now as this breaks the
 # octave bindings.


There are probably better ways to inject that flag...

if you want to have an example of a failure:
https://launchpad.net/ubuntu/+source/plplot/5.15.0+dfsg-8/+build/18212633

thanks for having a look

Gianfranco