[mythtv] Build error on Fedora rawhide

[Gary Buhrmaster]

On Sun, May 11, 2014 at 5:43 PM, Gary Buhrmaster
<gary.buhrmaster at gmail.com> wrote:
> On Sun, May 11, 2014 at 4:40 PM, Richard Shaw <hobbes1069 at gmail.com> wrote:
>> I was working on building a new fixes release when I ran into this on
>> Rawhide[1]... Building for F20 works fine...
...
> Not quickly, and I have to go do some errands, but here are my
> initial thoughts:

Looks to be a g++ bug with your specified -O2 optimization
flag, adding in -fno-devirtualize allows the compilation to
work.

(why is the rpmfusion build specifying so many configure
options?; yes, some are reasonable, and are part of the
Fedora standards, but some (especially the features)
should default just fine with proper packaging dependencies.
Also, some of the dependencies in the package no
longer appear correct.  The ones that popped up for
me were the libdvdread/nav ones (code is now within
MythTV).)


gcc bug 61085 looks like a possibility (although that
is based solely on the description, rather than any real
analysis).

One can either wait for various gcc fixes to roll out to
rawhide (you might want to get on the IP list for that
particular bug), or for now add in the switch to be able
to compile (but remember to remove it when the gcc
fixes are made available).

If you can produce a trivial test case, it may be valuable
to the gcc team in the case that that existing bug is
not the one you are hitting.

In any case, looks to be an upstream problem.

Gary