meson.build: Fix docker-test-build@alpine when including linux/errque…

…ue.h

A build error happens in alpine CI when linux/errqueue.h is included
in io/channel-socket.c, due to redefining of 'struct __kernel_timespec':

===
ninja: job failed: [...]
In file included from /usr/include/linux/errqueue.h:6,
                 from ../io/channel-socket.c:29:
/usr/include/linux/time_types.h:7:8: error: redefinition of 'struct __kernel_timespec'
    7 | struct __kernel_timespec {
      |        ^~~~~~~~~~~~~~~~~
In file included from /usr/include/liburing.h:19,
                 from /builds/user/qemu/include/block/aio.h:18,
                 from /builds/user/qemu/include/io/channel.h:26,
                 from /builds/user/qemu/include/io/channel-socket.h:24,
                 from ../io/channel-socket.c:24:
/usr/include/liburing/compat.h:9:8: note: originally defined here
    9 | struct __kernel_timespec {
      |        ^~~~~~~~~~~~~~~~~
ninja: subcommand failed
===

As above error message suggests, 'struct __kernel_timespec' was already
defined by liburing/compat.h.

Fix alpine CI by adding test to disable liburing in configure step if a
redefinition happens between linux/errqueue.h and liburing/compat.h.

[dgilbert: This has been fixed in Alpine issue 13813 and liburing]

Signed-off-by: Leonardo Bras <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Dr. David Alan Gilbert <[email protected]>
Signed-off-by: Dr. David Alan Gilbert <[email protected]>

meson.build

@@ -515,12 +515,23 @@ if not get_option('linux_aio').auto() or have_block
                            required: get_option('linux_aio'),
                            kwargs: static_kwargs)
 endif
+
+linux_io_uring_test = '''
+  #include <liburing.h>
+  #include <linux/errqueue.h>
+
+  int main(void) { return 0; }'''
+
 linux_io_uring = not_found
 if not get_option('linux_io_uring').auto() or have_block
   linux_io_uring = dependency('liburing', version: '>=0.3',
                               required: get_option('linux_io_uring'),
                               method: 'pkg-config', kwargs: static_kwargs)
+  if not cc.links(linux_io_uring_test)
+    linux_io_uring = not_found
+  endif
 endif
+
 libnfs = not_found
 if not get_option('libnfs').auto() or have_block
   libnfs = dependency('libnfs', version: '>=1.9.3',