[MacPorts] #64147: squashfs-tools: builds fail on 10.12 and earlier, due to missing symbol '_utimensat'

[MacPorts]

#64147: squashfs-tools: builds fail on 10.12 and earlier, due to missing symbol
'_utimensat'
---------------------+----------------------------
 Reporter:  mascguy  |      Owner:  quentinmit
     Type:  defect   |     Status:  assigned
 Priority:  Normal   |  Milestone:
Component:  ports    |    Version:
 Keywords:           |       Port:  squashfs-tools
---------------------+----------------------------
 This new port is failing to build on 10.12 and earlier, due to call
 `_utimensat`. The latter is missing on those earlier macOS releases.

 Example from the 10.12 buildbot:

 https://build.macports.org/builders/ports-10.12_x86_64-builder/builds/167925/steps
 /install-port/logs/stdio

 {{{
 cc  unsquashfs.o unsquash-1.o unsquash-2.o unsquash-3.o unsquash-4.o
 unsquash-123.o unsquash-34.o unsquash-1234.o swap.o compressor.o
 unsquashfs_info.o gzip_wrapper.o xz_wrapper.o lzo_wrapper.o lz4_wrapper.o
 zstd_wrapper.o read_xattrs.o unsquashfs_xattr.o -lpthread -lm -lz -llzma
 -llzo2 -llz4 -lzstd -o unsquashfs
 Undefined symbols for architecture x86_64:
   "_utimensat", referenced from:
       _create_inode in unsquashfs.o
 ld: symbol(s) not found for architecture x86_64
 }}}

 This *might* be fixable via use of MacPorts' `legacysupport` library. (Or,
 if that symbol isn't provided by the latter, it might be something we can
 add.) But need confirmation from the maintainers of `legacysupport`.

-- 
Ticket URL: <https://trac.macports.org/ticket/64147>
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