--- a/CMakeLists.txt	2026-06-01 23:53:16.498043856 -0400
+++ b/CMakeLists.txt	2026-06-01 23:53:23.910543615 -0400
@@ -312,13 +312,29 @@
     ${OPENSSL_SHARED_CRYPTO_LIBRARY}
     ${OPENSSL_SHARED_SSL_LIBRARY}
 )
-add_custom_command(
-    OUTPUT ${OPENSSL_BUILD_OUTPUT}
-    COMMAND ${OPENSSL_BUILD_COMMAND}
-    DEPENDS ${OPENSSL_SOURCES}
-    WORKING_DIRECTORY ${OpenSSL_BINARY_DIR}
-    VERBATIM
-)
+if (WIN32)
+    add_custom_command(
+        OUTPUT ${OPENSSL_BUILD_OUTPUT}
+        COMMAND ${OPENSSL_BUILD_COMMAND}
+        DEPENDS ${OPENSSL_SOURCES}
+        WORKING_DIRECTORY ${OpenSSL_BINARY_DIR}
+        VERBATIM)
+else()
+    set(_openssl_build_script "${CMAKE_CURRENT_BINARY_DIR}/BuildOpenSSL.cmake")
+    file(WRITE ${_openssl_build_script}
+        "execute_process(\n"
+        "    COMMAND ${OPENSSL_BUILD_COMMAND}\n"
+        "    WORKING_DIRECTORY ${OpenSSL_BINARY_DIR}\n"
+        "    RESULT_VARIABLE _r)\n"
+        "if(_r)\n"
+        "    message(FATAL_ERROR \"OpenSSL build failed: \${_r}\")\n"
+        "endif()\n")
+    add_custom_command(
+        OUTPUT ${OPENSSL_BUILD_OUTPUT}
+        COMMAND ${CMAKE_COMMAND} -P ${_openssl_build_script}
+        DEPENDS ${OPENSSL_SOURCES}
+        VERBATIM)
+endif()
 
 if(PROJECT_IS_TOP_LEVEL)
     add_custom_target(openssl-build ALL DEPENDS ${OPENSSL_BUILD_OUTPUT})