From 84ccc3e3411b6a7b26df33dd8db4a6f7c107beb7 Mon Sep 17 00:00:00 2001
From: Sebastian Pipping <sebastian@pipping.org>
Date: Mon, 3 Feb 2025 18:19:54 +0100
Subject: [PATCH] fuzzers|cmake: Check for working protobuf compiler

---
 expat/CMakeLists.txt | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/expat/CMakeLists.txt b/expat/CMakeLists.txt
index 1e6dcdb7..d021e813 100644
--- a/expat/CMakeLists.txt
+++ b/expat/CMakeLists.txt
@@ -786,6 +786,14 @@ if(EXPAT_BUILD_FUZZERS)
         UPDATE_COMMAND true
         INSTALL_COMMAND true)
 
+    # Check for availability of protobuf compiler to avoid hard-to-understand
+    # errors from make(1) down the line as seen with CMake 3.25.1 on Debian
+    if(NOT Protobuf_PROTOC_EXECUTABLE)
+        message(SEND_ERROR
+            "The protobuf compiler (protoc) could not be found. "
+            "Is it installed and working properly?")
+    endif()
+
     protobuf_generate_cpp(XML_LPM_FUZZER_PROTO_SRCS
                           XML_LPM_FUZZER_PROTO_HDRS
                           fuzz/xml_lpm_fuzzer.proto)