Commit 1dc162f5a3 for qemu.org

commit 1dc162f5a3d6866d6888d5bce1b8f7d458e828cf
Author: Paolo Bonzini <pbonzini@redhat.com>
Date:   Fri Dec 12 12:40:15 2025 +0100

    rust: skip compilation if there are no system emulators

    Otherwise, the Rust crates require the corresponding C code
    (e.g. migration/ for rust/migration/) but the dependencies of
    that C code, for example the trace files, have not been built.

    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/rust/meson.build b/rust/meson.build
index afbeeeb47a..bacb787910 100644
--- a/rust/meson.build
+++ b/rust/meson.build
@@ -1,3 +1,9 @@
+if not have_system
+  subdir_done()
+else
+  message('Rust enabled but it is only used by system emulators.')
+endif
+
 subproject('anyhow-1-rs', required: true)
 subproject('bilge-0.2-rs', required: true)
 subproject('bilge-impl-0.2-rs', required: true)
@@ -30,6 +36,7 @@ subdir('qemu-macros')

 subdir('common')
 subdir('bits')
+
 subdir('util')
 subdir('bql')
 subdir('migration')