qemu @9.2.0: error: call to undeclared function 'IOMainPort'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]

[chriskuku]

port install qemu fails (macOS BigSur, 11.7.10)

$ sudo port install qemu
--->  Computing dependencies for qemu
--->  Fetching archive for qemu
--->  Attempting to fetch qemu-9.2.0_0+cocoa+curses+spice+spice_protocol+target_arm+target_i386+target_x86_64+usb+vnc.darwin_20.x86_64.tbz2 from https://fra.de.packages.macports.org/qemu
--->  Attempting to fetch qemu-9.2.0_0+cocoa+curses+spice+spice_protocol+target_arm+target_i386+target_x86_64+usb+vnc.darwin_20.x86_64.tbz2 from https://packages.macports.org/qemu
--->  Attempting to fetch qemu-9.2.0_0+cocoa+curses+spice+spice_protocol+target_arm+target_i386+target_x86_64+usb+vnc.darwin_20.x86_64.tbz2 from https://vie.at.packages.macports.org/qemu
--->  Building qemu
Error: Failed to build qemu: command execution failed    
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_emulators_qemu/qemu/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets if you believe there is a bug.
Error: Processing of port qemu failed
$ 

[jmroot (Joshua Root)]

Please attach the main.log.

[jmroot (Joshua Root)]

:info:build ../qemu-9.2.0/block/file-posix.c:3942:18: error: call to undeclared function 'IOMainPort'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
:info:build  3942 |     kernResult = IOMainPort(MACH_PORT_NULL, &mainPort);
:info:build       |                  ^

Different function, but might effectively be a duplicate of #71857.

[Dave-Allured (Dave Allured)]

Replying to jmroot:

Different function, but might effectively be a duplicate of #71857.

Not really a duplicate. #71857 is originally about accessing the Hypervisor framework. This report for IOMainPort concerns file I/O. QEMU is strict about deprecating older macos versions. So these two tickets are about different deprecations, probably at different times.

Here is the QEMU commit that removed IOMainPort:
"Drop ifdef for macOS versions older than 12.0"
​https://gitlab.com/qemu-project/qemu/-/commit/e9c9d8dc3ba993384bc9553b617120ad4717345c

Same issue filed for upstream. Note, "won't fix" for macOS < 12.0, unfortunately. They say that even 12.x and 13.x are no longer officially supported.
​https://gitlab.com/qemu-project/qemu/-/issues/2694

[Dave-Allured (Dave Allured)]

The discussion in #71857 leads to this patch, which I think would fix this particular IOMainPort build error on BigSur/OS 11:
​https://github.com/koucyuu/qemu_catalina_patches/blob/master/patch-qemu-block-file-posix.diff

So how far does MacPorts want to go, patching QEMU to support older OS versions that upstream is actively discouraging? Tickets on both MacPorts and QEMU suggest ongoing interest within the legacy Mac user base.

[ryandesign (Ryan Carsten Schmidt)]

MacPorts probably doesn't want to patch qemu to reinstate support for old OS versions that upstream has removed.

But we could introduce ports for older versions of qemu that would work on older OS versions.

Has duplicate #72665.