diff --git a/3rd_party/pull-eigen.cmake b/3rd_party/pull-eigen.cmake
index adcfc7a1bc..1a76f5a8c5 100644
--- a/3rd_party/pull-eigen.cmake
+++ b/3rd_party/pull-eigen.cmake
@@ -42,5 +42,9 @@ if(PULL_EIGEN)
   execute_process(
     COMMAND git -c advice.detachedHead=false clone --depth=1 --branch=3.4.0 https://gitlab.com/libeigen/eigen.git
     WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
+    RESULT_VARIABLE GIT_RESULT
     )
+  if(NOT GIT_RESULT EQUAL 0)
+    message(FATAL_ERROR "Failed to clone Eigen from https://gitlab.com/libeigen/eigen.git: git exited with ${GIT_RESULT}. Check network connectivity, proxy settings, and git availability.")
+  endif()
 endif()
diff --git a/3rd_party/pull-valijson.cmake b/3rd_party/pull-valijson.cmake
index 13f6e3e408..c80d4838d6 100644
--- a/3rd_party/pull-valijson.cmake
+++ b/3rd_party/pull-valijson.cmake
@@ -16,5 +16,12 @@
 # This cmake script is expected to be called from a target or custom command with WORKING_DIRECTORY set to this file's location
 
 if ( NOT EXISTS valijson )
-  execute_process( COMMAND git -c advice.detachedHead=false clone --depth=1 --branch=v1.0.2 https://github.com/tristanpenman/valijson.git WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR})
+  execute_process(
+    COMMAND git -c advice.detachedHead=false clone --depth=1 --branch=v1.0.2 https://github.com/tristanpenman/valijson.git
+    WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
+    RESULT_VARIABLE GIT_RESULT
+    )
+  if(NOT GIT_RESULT EQUAL 0)
+    message(FATAL_ERROR "Failed to clone Valijson from https://github.com/tristanpenman/valijson.git: git exited with ${GIT_RESULT}. Check network connectivity, proxy settings, and git availability.")
+  endif()
 endif()