[PATCH] build-sys: error when slirp is not found and not disabled

[marcandre . lureau]

From: Marc-André Lureau <marcandre.lureau@redhat.com>

This is an alternative configure-time solution to "[PATCH] net:
print a more actionable error when slirp is not found".

See also "If your networking is failing after updating to the latest git
version of QEMU..." ML thread.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 8dc661363f..565096001d 100644
--- a/meson.build
+++ b/meson.build
@@ -657,6 +657,12 @@ if not get_option('slirp').auto() or have_system
   endif
 endif
 
+if not get_option('slirp').disabled() and not slirp.found()
+  error('libslirp is not explicitely disabled and was not found. ' +
+        'Since qemu 7.2, libslirp is no longer included as a submodule ' +
+        'fallback, you must install it on your system or --disable-libslirp.')
+endif
+
 vde = not_found
 if not get_option('vde').auto() or have_system or have_tools
   vde = cc.find_library('vdeplug', has_headers: ['libvdeplug.h'],
-- 
2.37.3