mediainfolib @23.03 fails to build on mavericks

[tehcog (tehcog)]

:info:build In file included from /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/algorithm:627:
:info:build /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/memory:1585:20: error: object expression of non-scalar type 'ZenLib::Ztring [4]' cannot be used in a pseudo-destructor expression
:info:build                 __p->~_Tp();
:info:build                 ~~~^

Please see attached main.log

[tehcog (tehcog)]

main.log

[ctreleaven (Craig Treleaven)]

This is the same error as reported on the Mavericks buildbot:

​https://build.macports.org/builders/ports-10.9_x86_64-builder/builds/225618/steps/install-port/logs/stdio

The reported error doesn't really mean anything to me. I'm guessing that a newer version of clang is just required?

[jmroot (Joshua Root)]

In generic contexts, the destructor call syntax can be used with an object of non-class type; this is known as pseudo-destructor call

• ​https://en.cppreference.com/w/cpp/language/destructor

Furthermore,

The expr must be an expression of scalar type

• ​https://en.cppreference.com/w/cpp/language/operator_member_access#Built-in_member_access_operators

So the code being compiled is certainly ill-formed here, but I couldn't tell you if that's because of a bug in the mediainfolib code or in the older stdlib.

[ryandesign (Ryan Carsten Schmidt)]

We have successful buildbot builds on Mac OS X 10.6 (using MacPorts clang 11) and 10.7 (using MacPorts clang 15); 10.6 didn't ship with libc++ from Apple so it uses our newer libc++ but 10.7 uses the oldest libc++ Apple ever shipped which shows that just using a newer compiler should fix it. We have build failures on 10.8-10.11 using Xcode clang and successful builds on 10.12 and later. So blacklisting {clang < 900} should at least work around the issue. Probably also a good idea to report the problem to the developers in case they can fix the code to work with older compilers.

[ctreleaven (Craig Treleaven)]

In 1017a892fca66df3febea4f7115bffa59d82da3d/macports-ports (master):

mediainfolib: attempt to fix build on older systems

See #67223

[jmroot (Joshua Root)]

Replying to ryandesign:

10.6 didn't ship with libc++ from Apple so it uses our newer libc++ but 10.7 uses the oldest libc++ Apple ever shipped which shows that just using a newer compiler should fix it.

Perhaps it's an overly fine distinction since the fix is the same either way, but we only use the system libc++ runtime lib with macports-clang, while much of the C++ stdlib is headers which we ship and use with those compilers.

[ctreleaven (Craig Treleaven)]

Replying to tehcog:

Hi: Can you please do a 'port selfupdate" and try again? Please report back if you're able to install successfully. Thanks,

[ryandesign (Ryan Carsten Schmidt)]

That change resulted in successful buildbot builds on 10.9, 10.10, and 10.11. The 10.8 builder is busy and hasn't gotten around to trying it yet but it seems likely it'll succeed too.

[tehcog (tehcog)]

Replying to ctreleaven:

Hi: Can you please do a 'port selfupdate" and try again? Please report back if you're able to install successfully. Thanks,

Sorry about not responding - had a router meltdown here that took a few days to fix. I installed the lib, and tested the associated executable. Everything looks good. Thanks for your help. Regards