Re: mpv, ffmpeg seg fault in macOS catalina

[Michael Newman via macports-users]

Thanks. I’ve used the migration process many times in the past, so no worries.

I appreciate your taking the time to reply.

> On Oct 19, 2019, at 10:08, Chris Jones  wrote:
> 
>> If I upgrade to Catalina (I already have Xcode 11.1) and install MacPorts 
>> for Catalina will ffmpeg stop working?
> 
> As long as you follow the migration guide correctly, no.
> 
> https://trac.macports.org/wiki/Migration 
> 
> 

Re: mpv, ffmpeg seg fault in macOS catalina

[Michael Newman via macports-users]

I’m sorry, but I don’t understand most of what was written in this thread, but 
I do have a simple question:

If I upgrade to Catalina (I already have Xcode 11.1) and install MacPorts for 
Catalina will ffmpeg stop working?

> On Oct 18, 2019, at 19:00, Gill Bates  > wrote:
> 
> I recently updated to catalina (10.15) and Xcode (11.1), installed MacPorts 
> from source (2.6.1) and had it build mpv and its dependencies. However, mpv 
> (and ffmpeg for example) do not run

Re: mpv, ffmpeg seg fault in macOS catalina

[Gill Bates]

Thanks all for the explanations and workaround. 


From: "Mojca Miklavec"  
To: "smogus"  
Cc: "macports-users"  
Sent: Friday, October 18, 2019 5:02:55 AM 
Subject: Re: mpv, ffmpeg seg fault in macOS catalina 



V čet., 17. okt. 2019 22:58 je oseba Gill Bates < [ mailto:smo...@shaw.ca | 
smo...@shaw.ca ] > napisala: 



I recently updated to catalina (10.15) and Xcode (11.1), installed MacPorts 
from source (2.6.1) and had it build mpv and its dependencies. However, mpv 
(and ffmpeg for example) do not run apparently related to some new default 
compiler option enforcing 16 byte stack alignment? See: 
[ https://trac.ffmpeg.org/ticket/8073 | https://trac.ffmpeg.org/ticket/8073 ] 
[ https://github.com/mpv-player/mpv/issues/7053 | 
https://github.com/mpv-player/mpv/issues/7053 ] 
[ https://forums.developer.apple.com/thread/121887 | 
https://forums.developer.apple.com/thread/121887 ] 



I first saw [ https://github.com/LuaJIT/LuaJIT/issues/518 | 
https://github.com/LuaJIT/LuaJIT/issues/518 ] , but that one eventually leads 
to the same thread linked above. 


BQ_BEGIN

The advice seems to be to revert Xcode but will rebuilding everything with 
Xcode 10.3 on macos 10.15 really be a workaround? Or is a better choice to 
modify portfiles to include the CFLAG option to disable stack checks as 
mentioned in the linked posts and use Xcode 11.1? 

BQ_END

Workaround is to either blacklist the compiler which has this option turned on 
by default (which is what Chris replied) or in fact use a flag to disable this. 
But disabling this flag is not needed for non-broken compilers, so it's 
probably better to just blacklist the compiler, and the latest compiler with be 
automatically used again when the bug gets fixed. 


BQ_BEGIN

"Part B" is a question for my understanding, is this a really an Xcode/compiler 
issue or a problem with the source software packages? 

BQ_END

I would say that this is in fact an issue with the compiler. As they said, the 
bug has been present before, it's just that nobody noticed it until it was 
switched on by default. I've seen an email saying that this is likely to be 
fixed in one of the next Xcode updates, so it's just a matter of time. 

I believe this affects only source code which uses some heavy optimisations, 
which is why you would not see it in most of the software where high 
performance is not crucially important for the functionality. 

Mojca 

Re: mpv, ffmpeg seg fault in macOS catalina

[Chris Jones]

Hi,

Workaround is to either blacklist the compiler which has this option 
turned on by default (which is what Chris replied) or in fact use a flag 
to disable this. But disabling this flag is not needed for non-broken 
compilers, so it's probably better to just blacklist the compiler, and 
the latest compiler with be automatically used again when the bug gets 
fixed.


Currently I black list {clang > 1099}, so anything in current and future 
Xcode 11 versions. The (insider) claim was Xcode 11.2 'should' address 
this, but last I heard 11.2 beta 2 still had the problem, so time will tell.


Once the fixed clang version is known, the above blacklists can then be 
adjusted to make them non-open ended, but we need to know the fixed 
version first...


Chris

Re: mpv, ffmpeg seg fault in macOS catalina

[Mojca Miklavec]

V čet., 17. okt. 2019 22:58 je oseba Gill Bates  napisala:

> I recently updated to catalina (10.15) and Xcode (11.1), installed
> MacPorts from source (2.6.1) and had it build mpv and its dependencies.
> However, mpv (and ffmpeg for example) do not run apparently related to some
> new default compiler option enforcing 16 byte stack alignment? See:
> https://trac.ffmpeg.org/ticket/8073
> https://github.com/mpv-player/mpv/issues/7053
> https://forums.developer.apple.com/thread/121887
>

I first saw https://github.com/LuaJIT/LuaJIT/issues/518, but that one
eventually leads to the same thread linked above.

 The advice seems to be to revert Xcode but will rebuilding everything with
> Xcode 10.3 on macos 10.15 really be a workaround? Or is a better choice to
> modify portfiles to include the CFLAG option to disable stack checks as
> mentioned in the linked posts and use Xcode 11.1?
>

Workaround is to either blacklist the compiler which has this option turned
on by default (which is what Chris replied) or in fact use a flag to
disable this. But disabling this flag is not needed for non-broken
compilers, so it's probably better to just blacklist the compiler, and the
latest compiler with be automatically used again when the bug gets fixed.

"Part B" is a question for my understanding, is this a really an
> Xcode/compiler issue or a problem with the source software packages?
>

I would say that this is in fact an issue with the compiler. As they said,
the bug has been present before, it's just that nobody noticed it until it
was switched on by default. I've seen an email saying that this is likely
to be fixed in one of the next Xcode updates, so it's just a matter of time.

I believe this affects only source code which uses some heavy
optimisations, which is why you would not see it in most of the software
where high performance is not crucially important for the functionality.

Mojca

Re: mpv, ffmpeg seg fault in macOS catalina

[Christopher Jones]

Hi,

10.15 issues are worked around in

https://github.com/macports/macports-ports/commit/36c3a9a2844ab979be1388280922b25d1f7b56ce
 


https://github.com/macports/macports-ports/commit/2de6959b098cb95883863a2cf46575dfcf4c211c
 


They blacklist Xcode 11 clang, and thus the builds fallback to one of MacPorts 
MP’s clang compilers (9.0). 

Running Xcode 10 on macOS10.15 is unnecessary, and not really a good idea.

For ‘Part B’ difficult to say as long as Xcode has issues (which I understand 
as off 11.1 it does). Until those are addressed hard to say if the project 
themselves also have issues to address.

Chris

> On 17 Oct 2019, at 9:58 pm, Gill Bates  wrote:
> 
> I recently updated to catalina (10.15) and Xcode (11.1), installed MacPorts 
> from source (2.6.1) and had it build mpv and its dependencies. However, mpv 
> (and ffmpeg for example) do not run apparently related to some new default 
> compiler option enforcing 16 byte stack alignment? See:
> https://trac.ffmpeg.org/ticket/8073 
> https://github.com/mpv-player/mpv/issues/7053 
> 
> https://forums.developer.apple.com/thread/121887 
> 
> 
> The advice seems to be to revert Xcode but will rebuilding everything with 
> Xcode 10.3 on macos 10.15 really be a workaround? Or is a better choice to 
> modify portfiles to include the CFLAG option to disable stack checks as 
> mentioned in the linked posts and use Xcode 11.1?
> 
> "Part B" is a question for my understanding, is this a really an 
> Xcode/compiler issue or a problem with the source software packages?
> 
> Thanks in advance for any advice.



smime.p7s
Description: S/MIME cryptographic signature

mpv, ffmpeg seg fault in macOS catalina

[Gill Bates]

I recently updated to catalina (10.15) and Xcode (11.1), installed MacPorts 
from source (2.6.1) and had it build mpv and its dependencies. However, mpv 
(and ffmpeg for example) do not run apparently related to some new default 
compiler option enforcing 16 byte stack alignment? See: 
[ https://trac.ffmpeg.org/ticket/8073 | https://trac.ffmpeg.org/ticket/8073 ] 
[ https://github.com/mpv-player/mpv/issues/7053 | 
https://github.com/mpv-player/mpv/issues/7053 ] 
[ https://forums.developer.apple.com/thread/121887 | 
https://forums.developer.apple.com/thread/121887 ] 

The advice seems to be to revert Xcode but will rebuilding everything with 
Xcode 10.3 on macos 10.15 really be a workaround? Or is a better choice to 
modify portfiles to include the CFLAG option to disable stack checks as 
mentioned in the linked posts and use Xcode 11.1? 

"Part B" is a question for my understanding, is this a really an Xcode/compiler 
issue or a problem with the source software packages? 

Thanks in advance for any advice.