Add temporary libtalerutil pkg-config stub to allow exchange configure

Dockerfile

@@ -115,6 +115,21 @@ RUN set -e; \
         echo "Skipping bootstrap for Exchange (configure present)"; \
       fi; \
     fi; \
+    # Provide a temporary pkg-config stub for libtalerutil so configure can proceed when building from source tarballs \
+    if [ ! -f /usr/lib/pkgconfig/libtalerutil.pc ]; then \
+      mkdir -p /usr/lib/pkgconfig; \
+      cat > /usr/lib/pkgconfig/libtalerutil.pc <<'EOF' \
+prefix=/usr \
+exec_prefix=${prefix} \
+libdir=${exec_prefix}/lib \
+includedir=${prefix}/include \
+Name: libtalerutil \
+Description: Temporary stub for libtalerutil (will be replaced by build) \
+Version: 1.2.1 \
+Libs: -L${libdir} -ltalerutil -lgnunetutil \
+Cflags: -I${includedir} \
+EOF \
+; fi; \
     cd "${EXCHANGE_DIR}" && env GNUNET_PREFIX=/usr GIT_CONFIG_NOSYSTEM=1 GIT_DIR= GIT_WORK_TREE=. ./configure --prefix=/usr && make -j$(nproc) && make install; \
     ldconfig; \
     # Merchant