Fix: Add _DISABLE_CONSTEXPR_MUTEX_CONSTRUCTOR to prevent crashes (#1814)

EllieTellie · a-maurice · web-flow · commit e645ebff6821 · 2026-01-13T17:50:32.000-08:00
* Fix: Add _DISABLE_CONSTEXPR_MUTEX_CONSTRUCTOR for compatibility with older MSVC runtimes.

* Document the issue reference as suggested by Gemini Code assist.

---------

Co-authored-by: a-maurice &lt;amaurice@google.com&gt;
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -199,6 +199,9 @@ if (MSVC)
       $<$<CONFIG:Release>:/MD>
   )
   endif()
+  # Disable constexpr mutex constructor to fix crashes on older vcruntimes.
+  # See: https://github.com/microsoft/STL/issues/4730
+  add_compile_definitions(_DISABLE_CONSTEXPR_MUTEX_CONSTRUCTOR)
 endif()
 
 # Set variables that are used by download_external_sources.

Original file line number	Diff line number	Diff line change
`@@ -199,6 +199,9 @@ if (MSVC)`
`199`	`199`	`$<$<CONFIG:Release>:/MD>`
`200`	`200`	`)`
`201`	`201`	`endif()`
	`202`	`+ # Disable constexpr mutex constructor to fix crashes on older vcruntimes.`
	`203`	`+ # See: https://github.com/microsoft/STL/issues/4730`
	`204`	`+ add_compile_definitions(_DISABLE_CONSTEXPR_MUTEX_CONSTRUCTOR)`
`202`	`205`	`endif()`
`203`	`206`
`204`	`207`	`# Set variables that are used by download_external_sources.`