[PATCH] Makefile: Report error and stop if we can't set TARGET

[Stefano Brivio <sbrivio@redhat.com>]

I don't think it's necessarily productive to check all the possible
error conditions in the Makefile, but this one is annoying: issue
'make' without a C compiler, then install one, and build again.

Then run passt and it will mysteriously terminate on epoll_wait(),
because seccomp.h is good enough to build against, but the resulting
seccomp filter doesn't allow any system call. Not really fun to debug.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
 Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Makefile b/Makefile
index 1fce737..464eef1 100644
--- a/Makefile
+++ b/Makefile
@@ -16,6 +16,7 @@ VERSION ?= $(shell git describe --tags HEAD 2>/dev/null || echo "unknown\ versio
 DUAL_STACK_SOCKETS := 1
 
 TARGET ?= $(shell $(CC) -dumpmachine)
+$(if $(TARGET),,$(error Failed to get target architecture))
 # Get 'uname -m'-like architecture description for target
 TARGET_ARCH := $(firstword $(subst -, ,$(TARGET)))
 TARGET_ARCH := $(patsubst [:upper:],[:lower:],$(TARGET_ARCH))
-- 
@@ -16,6 +16,7 @@ VERSION ?= $(shell git describe --tags HEAD 2>/dev/null || echo "unknown\ versio
 DUAL_STACK_SOCKETS := 1
 
 TARGET ?= $(shell $(CC) -dumpmachine)
+$(if $(TARGET),,$(error Failed to get target architecture))
 # Get 'uname -m'-like architecture description for target
 TARGET_ARCH := $(firstword $(subst -, ,$(TARGET)))
 TARGET_ARCH := $(patsubst [:upper:],[:lower:],$(TARGET_ARCH))
-- 
2.43.0