fuzz: add gitlab build support, use clang

.gitlab-ci.yml

@@ -257,6 +257,13 @@ linux64_cxx20-build:
   variables:
     BUILD_TARGET: linux64_cxx20
 
+linux64_fuzz-build:
+  extends: .build-template
+  needs:
+    - x86_64-unknown-linux-gnu-debug
+  variables:
+    BUILD_TARGET: linux64_fuzz
+
 linux64_tsan-build:
   extends:
     - .build-template

ci/dash/matrix.sh

@@ -75,6 +75,14 @@ elif [ "$BUILD_TARGET" = "linux64_tsan" ]; then
   export BITCOIN_CONFIG="--enable-zmq --enable-reduce-exports --enable-crash-hooks --with-sanitizers=thread"
   export CPPFLAGS="-DDEBUG_LOCKORDER -DENABLE_DASH_DEBUG -DARENA_DEBUG"
   export PYZMQ=true
+elif [ "$BUILD_TARGET" = "linux64_fuzz" ]; then
+  export HOST=x86_64-unknown-linux-gnu
+  export DEP_OPTS="NO_UPNP=1 DEBUG=1"
+  export BITCOIN_CONFIG="--enable-zmq --disable-ccache --enable-fuzz --with-sanitizers=fuzzer,address,undefined CC=clang CXX=clang++"
+  export CPPFLAGS="-DDEBUG_LOCKORDER -DENABLE_DASH_DEBUG -DARENA_DEBUG"
+  export PYZMQ=true
+  export RUN_UNITTESTS=false
+  export RUN_INTEGRATIONTESTS=false
 elif [ "$BUILD_TARGET" = "linux64_cxx20" ]; then
   export HOST=x86_64-unknown-linux-gnu
   export DEP_OPTS="NO_UPNP=1 DEBUG=1"

contrib/containers/ci/Dockerfile

@@ -15,6 +15,7 @@ RUN apt-get update && apt-get install $APT_ARGS \
     bsdmainutils \
     curl \
     ccache \
+    clang \
     cmake \
     git \
     g++ \